So, we've worked our way through half of the Player's Handbook 2 classes, and posting on the board has slowed down a bit which I do apologize for but I have a new job and it is taking time away from writing these unfortunately. The pace will pick back up a bit.
However, we press onward. There will be a change in the format for this guide from my previous ones. I have shortened the race section as I feel like a full paragraph is more than what is necessary, and I feel like I'm saying the same things over and over again for each race, so they will be shortened to merely a couple paragraphs. Everything else will be just as in-depth as before.
So what exactly are we invoking?
To be honest, the flavor of Invokers confuses me a little. I assume they are kind of like Favored Souls from 3.5, in that they are less about being really devoted to their god and being granted power in return, and are instead just innately capable of calling down divine badassery. Kind of like the difference between sorcerers and wizards, but on a divine tip instead of an arcane one.
Invokers are a controller, and play very similar to orb wizards, but have just enough differences to give them their own flavor. They are also the first instance of summoning, and they can summon a variety of angels into battle over the course of their levels. They also have a lot of very large area attacks that don't deal damage but give a lot of enemies a status effect which can be very useful. They also have a few good utility buffs to aid allies and can wear chainmail so they can have a decent AC without having to work it into their ability scores.
Regardless of build you get a Channel Divinity power called Rebuke Undead that is much like the cleric's Turn Undead, except its a Close Blast 5 and dazes them. It is very useful in undead-centric campaigns, but you probably want another use of Channel Divinity that you find useful for encounters that don't include such enemies.
Preservation or Wrath
As an invoker you get to choose between two covenants. Each covenant comes with a different channel divinity power, an innate class feature, and affects the way many powers work for you.
The covenant of preservation is the way you probably want to go if you want to really help your allies make the most of positioning and provide them with a some useful buffs. Whenever you use an encounter or daily power you can slide an ally within ten squares of you one square. This allows you to slide enemies into flanking positions for your allies, or remove your allies from the same type of positions, as well as help an Avenger keep his oath of enmity, or move allies out of a Sorcerer's area attacks. You also get a channel divinity power called Preserver's Rebuke which allows you to gain an attack roll bonus equal to your Intelligence modifier against an enemy who attacks an ally of yours, as long as that enemy is within 10 squares as an immediate reaction to the ally being hit. This is a very good power, and can help you land daily powers when you need them the most, and is really great against solo monsters who are often harder to hit, but who need to be dazed/stunned/immobilized the most.
The covenant of wrath is for the more offensive minded Invoker. The abilities are all about punishing your enemies, and they often deal more damage and are more about deterring the bad guys than aiding the good guys. Whenever you use an encounter or daily power you add 1 to the damage roll for each target of the power. This is a neat bonus on low levels when a few extra damage can mean the difference between whether or not an enemy gets to attack for another round, but on higher levels it doesn't scale well since you probably won't be hitting that many more targets with each power. Covenant of wrath also grants you the Channel Divinity power Armor of Wrath which is an immediate reaction you use when an enemy within 5 squares hits you. It deals radiant damage equal to your constitution to them, and pushes them two squares, which can allow you for an easier getaway. Its a pretty good power and can be improved with feats, but I think that Preserver's Rebuke is better overall. Luckily, Wrath gives some really sweet bonuses to your powers, adding pushes, extra damage, and penalizing saving throws.
All of your attacks use Wisdom, so that is going to be where you want most of your points. If you are a Preserving Invoker you want to prioritize Intelligence next, while if you're a Wrathful Invoker you will want to prioritize Constitution. These key abilities come into play with many of their powers, improving them in various ways.
After that you can up Dexterity or Constitution depending on your build, to raise your weakest defense, but to be honest, there's little reason in my mind not to just buy an 18 in wisdom, a 14 in your secondary ability score and just not care about the rest. This might change when Divine Power comes out and gives us more feats, but as of now, I would probably go all out in those two scores unless I had a multiclass build in mind and I needed another ability score for it.
As far as ability scores go Devas make the ideal Covenant of Preservation Invokers, while Dwarves make the ideal Covenant of Wrath Invokers. Both have universally useful racial capabilities as well, so if you want an easy race choice, you can't go wrong with either of them. However, my favorite race for the class is Human, so that you can grab a third at-will, raise your defenses, and get an extra feat. This class really benefits from having a third at-will since they have quite a few good ones that are useful in different situations.
Elves make good and mobile Invokers of any type, and being able to shift over difficult terrain makes it harder for an enemy to pin them down. Eladrin make decent Preserving Invokers, and can teleport out of dangerous situations to much the same effect. Half-Elves make good Wrathful Invokers, and can use their dilettante power to grab Sacred Flame from the clerics to help give saving throws to their allies, or Lance of Faith to give their allies an attack boost. Tieflings are the last race from Player's Handbook One that really make sense for Invokers, and only as Preserving ones, but their racial abilities work fine for the class, helping them lock down bloodied enemies, and aiding against a foe that manages to hit them.
Genasi have the intelligence to make good preserving Invokers, and can take Earthsoul or Firesoul as their manifestation to punish enemies that get too close, or take Windsoul or Watersoul to become more mobile.
Gnomes make good Preserving Invokers, and have a good defensive power like many of the races cut out for the job, and Goliaths can be okay as Wrathful Invokers though other than the constitution bonus they don't get a lot to help with the job. Both kinds of Shifters get a Wisdom bonus, so both are capable as Invokers of any type, and both have a decent racial power that works for just about any class, so it applies here.
You get Religion automatically and then three others. Only one of these is keyed to Wisdom, and that's Insight so you might as well take it. It could be fun to call out NPCs on their lies with the vengeful tone of a fire and brimstone preacher after all. After that it might depend on your character, if you're a Wrath build you could take Endurance since you'd have a decent bonus in it, while if you're Preserving you could take History and/or Arcana for the same reason. From what's left you're basically choosing between Diplomacy or Intimidate, neither of which will have a particularly great bonus for you, so I'd just think about your character's manner when making the choice. Does he make demands or does he make proposals?
You make area attacks with an implement, so Implement Expertise is a foregone conclusion again. Distant Advantage could be nice if you have a lot of melee allies to help you out, but there's not a lot of general feats that help your offensive capabilities currently. You could take a Channel Divinity feat like Raven Queen's Blessing or Armor of Bahamut if your deity allows, but Preserver's Rebuke is pretty good and Armor of Wrath is great once you have the feats that improve it so it may not be necessary. I expect this to change with Divine Power's release, but until then, I'd focus on the class specific feats and the defense.
Defensively you could take Toughness because you class has very few hit points, as well as Durable because you don't have a lot of surges either. Defensive Mobility could be useful if you find yourself in a lot of tight small areas where you either have to cast next to an enemy or not at all, but again there's not a lot of real need here. Your allies should be protecting you well enough that you don't need to up your defenses a lot.
For utility you probably want to take Improved Initiative, because as an Invoker being able to go first means you can take enemies out of the fight quickly, and lay down a good Area attack before your allies place themselves in it. You are also going to have plenty of extra feat space (again, this could change with Divine Power) on this character, so you could take Linguist or Skill Focus to make your character very useful outside of combat as well.
The Invoker's class specific feats are all good to differing degrees. Invoker's Defense allows them to gain +2 AC against an enemy within 3 squares of you if you hit him with an invoker power, and the bonus lasts until the start of your next turn, but if you find yourself always having plenty of room between you and your enemies you probably don't need this feat particularly. Resonating Covenant gives you +1 to hit with your at-will attacks on the turn after you attack with an encounter or daily power. This can be nice, but you really want to hit with your dailies and encounters more, so this bonus is a little extraneous. It can keep you in the fight once your party is down to at-wills though, so if you can afford it, definitely take it. Insightful Preservation improves the Preserver's Rebuke Channel Dvinity power, giving the ally hit by the triggering attack a decent amount of temporary hit points. This is an excellent bonus, and makes a good power great, especially since its something you will without a doubt make use of every encounter, and your defender will be thankful for the extra cushioning on his hit points. Scouring Wrath is the last Invoker feat in heroic tier and it improves armor of wrath, making the target of the power gain vulnerable 2 to all damage until the end of your next turn. This can be good because it can add a lot of damage, but it depends largely on initiative order, if the monster you hit goes right before you, you don't get as much time to make use of the bonus as you would if you had just taken your turn, letting all your allies gain +2 damage against the monster.
Invokers have five different at-will powers to choose from, and its going to be a tough choice for your character which two make the cut, unless you're a human then you'll find it easier.
Avenging Light is a single target attack with a range of ten squares. It deals 1d10 plus Wisdom radiant damage, and you get to add your constitution modifier if you have a bloodied ally adjacent to the target. It targets Fortitude and can be used as a ranged basic attack. For Wrathful Invokers this can be a good power to fall back on once the heavier artillery has been used up, and can deal decent damage for a controller power. If you have a character who can grant you a basic attack it can also nice for that, however there is another power that can be used as a basic ranged attack that has greater utility.
Divine Bolts is a cool power because it targets one or two creatures within 10 squares, so you don't have to worry about lining up a blast or burst area to hit two enemies on your turn. It deals lightning damage which isn't as good as radiant since few enemies are vulnerable to it, and it doesn't deal very much damage but it can be great for taking out minions, and it targets reflex, if you want an at-will that targets that defense.
Grasping Shards is one of two Invoker at-wills that attack a burst 1 within 10 squares. It targets fortitude and only deals Wisdom modifier damage until you hit epic tier, but it also slows all the enemies, and it deals radiant damage so you can still deal decent damage to undead with it. Its one of my favorite at-wills for the class, and I recommend taking it if you can.
Sun Strike targets Reflex, and can be used as a ranged basic attack. It deals 1d8 plus Wisdom modifier radiant damage, and you can slide the target 1 square if you hit it, which can help position enemies in a really versatile way that powers that push and pull can't. I think its probably better than Avenging Light, so if you decided you don't want that power, then take this one so that you have a good ranged basic attack.
Vanguard's Lightning is the second burst 1 power that you have and it targets reflex and deals lightning damage. While it deals more damage than Grasping Shards, its effect isn't as universally useful. Vanguard's Lightning makes it so that the targets take extra lightning damage if they make opportunity attacks until the end of your next turn, so you can do this to penalize enemies you or an ally need to run past, but otherwise it's not that useful and isn't as good of a damage type.
The first Encounter Power option you have is Astral Terror. It's a close burst three that targets only enemies, and attacks will which is good since you don't have an at-will that targets it. All enemies hit by the power get pushed 2 squares, which can be useful, but sometimes your melee allies might not appreciate the change of positioning so much. It deals psychic damage which almost no monster (possibly even no monster now that I think about it) is vulnerable to, but it does open up the psychic lock feat as an option in paragon tier which is a great feat.
Blades of Astral Fire is another area attack, though this one targets a burst 1 within 10 and attacks reflex. It deals radiant damage to each enemy within the burst and allies get +2 AC for being within it. If you have Covenant of Preservation this bonus is actually equal to your Intelligence modifier plus one. This power is great since you don't have to worry about friendly fire with it, and it gives your allies a bonus. You can throw it right into the thick of melee and it will not only hurt your enemies but also protect your friends. Its an easy power choice for a Preserving Invoker, and I might even pick it if I chose Wrath.
Spear of the Inquisitor is a straightforward ability, it deals 1d10 plus Wisdom modifier radiant damage, targets reflex and immobilizes the target until the end of your next turn. It's great against elites or solos that don't have ranged attacks, especially if they're undead.
Thunder of Judgement targets one, two, or three creatures within Ranged 10 so it has a great amount of versatility when picking targets. It deals extra damage if you only target one creature so its useful even when you don't have a crowd to thin, and if you're a Wrathful build than you can push the target a number of squares equal to your Constitution modifier. If only it dealt radiant damage and targeted Will it would be perfect.
You get quite a variety in your level 1 Daily Powers, starting with Angelic Echelon. It's another close burst 3 that only targets enemies and again it targets Will. It deals 1d6 plus Wisdom modifier radiant damage, and if the target attacks before the end of your next turn it takes 5 radiant damage. This is another good power, especially if fighting a lot of undead creatures since that 5 damage is more likely going to be 10 or 15, which even mindless undead are going to be loath to take.
Binding Invocation of Chains is a close burst 10 attack. That's right, close burst 10! It only targets enemies so you don't have to worry about the extremely difficult task of keeping your allies 10 squares away from you, but it doesn't deal any damage. However, it does slow every enemy in the area until they make a save, and it slows them until the end of your next turn even if you miss. This makes it a very good power, especially if you have a range-heavy party and delaying the enemies from reaching you allows you a round or two of free shots.
Purging Flame seems kind of underwhelming to be honest. It does deal 1d10 plus Wisdom modifier fire damage and 10 ongoing fire damage, but any monster that you'd really want to hit with that kind of ongoing damage at level 1 is pretty likely to save against it after one round of it. It is nice that it still gives 5 ongoing damage if you miss though, regardless I just can't see this as anything but the worst choice for a daily power.
The last daily power is your first summoning ability, Angel of Fire. It summons a medium sized angel in an unoccupied square within range 5. The angel has speed 6 and can fly at the same speed, though you have to use your actions to move it. Its standard action is a close burst 1 which means you can use it to make an area attack round after round, dealing a decent amount of fire damage each round. The angel also has a good opportunity attack, so positioning it in a way to take advantage of that is key to maximizing your uses of this power.
Once you hit level 2 and gain a utility power you have a good assortment to pick from. Divine Call is an encounter power that pulls one or two allies within 10 squares 3 squares each. This can be nice to bail an ally out of trouble, or since its a minor action, set up positioning for your own abilities or another allies without taking the majority of your turn to do it.
Emissary of the Gods gives you +5 to your next diplomacy or intimidate check. If you use it during a skill challenge it gives you an extra success if you make the check with it. Its cool, but since its not that applicable outside of skill challenges in most D&D games, I'd skip it.
Shroud of Awe lets you speak with a thunderous voice that stretches 500 feet. It can increase your next intimidate check, and you can do it every encounter, but again I'd skip this in favor of a more combat applicable power.
Shroud of Warning gives you and each ally an initiative bonus once per day, but isn't that useful if you're a Wrathful build. It's good but I'd prefer either Divine Call or Wall of Light actually.
Wall of Light is a nifty power simply because there aren't enough Wall powers in the game and this one is one of the few that creates an actually defensive wall instead of an offensive one. The wall it conjures is 5 squares long and grants 5 temporary hit points to any ally that starts their turn inside it. It also grants +1 AC to anyone who is inside it, so in fights where your characters don't have to move a lot it can provide a great defensive boost.
The most obvious choice is Cleric, especially if your team is short on the Leader role, but Shamans also work for the same goal. Druids or Avengers also use Wisdom for attacks, so those can be available multiclass options though neither is really optimal.
For Preserving Builds you can also take Swordmage powers or Wizard powers but again, these aren't very useful mechanically while if you are Wrath you can take some of the good Warlock powers, which can actually be helpful since Dire Radiance helps keep enemies at bay, and there are plenty of good solid damage dealing Warlock powers that use Constitution if you want to make up for your party's lack of strikers.
If you aren't missing some kind of role though, I wouldn't really multiclass an Invoker since they get plenty of cool options for themselves as far as feats and powers are concerned.
Invokers are pretty straightforward to play. Hinder foes, and help position enemies and allies in the most advantageous position you can whenever its a possibility. Listen to your allies needs, and you will often find yourself with the tool for the job. Use your angels to help block off hallways and prevent enemies from getting to you and the other casters whenever you can and consider taking some of the large area status effect powers to really help give your party an edge.
There aren't a lot of tricks for this class that I haven't mentioned already unfortunately so I'll have to end the guide here. Hopefully it won't take me quite as long to do the Shaman, even though I consider it to be the most complicated class in the game.