Avengers have this power:
Avenger, PHB2 wrote:
OATH OF ENMITY
Suck on my sword, villains! Suck it dry!
Encounter (Special) * Divine
Minor Action -- Close burst 10
Target: One enemy you can see in burst.
Effect: When you make a melee attack against the target and the target is the only enemy adjacent to you, you make two attack rolls and use either result. This effect lasts until the end of the encounter or until the target drops to 0 hit points, at which point you regain the use of this power.
If another effect lets you roll twice and use the higher result when making an attack roll, this power has no effect on that attack. If an effect forces you to roll twice and use the lower result when making an attack roll, this power has no effect on that attack roll either.
If an effect lets you reroll an attack roll and you rolled twice because of this power, you reroll both dice.
They also have Channel Divinity, too, which is actually really nice when you want to get your Righteous Wrath of Tempus on.
But anyway, avenger powers suck monkey fuck. They have no powers that let them take more than one attack and no bonus damage feature. Furthermore, because they're a WIS/DEX/INT class, they don't actually qualify for the good weapon feats. They have Oath of Enmity which you think would be awesome for critical hits, but no, they can't even grab Weapon Mastery because their stat array sucks balls.
They're supposed to get their damage from using their Oath of Enmity feature. Which is supposed to make it okay. It doesn't, but there's still hope!
What you want to do is go Eternal Seeker and swap out EVERY SINGLE ONE OF YOUR FUCKING POWERS. And because the dumbfucks who designed this edition are, well, dumb as a bag of fermented menses the 'real' combat classes use STR as a primary attack stat. Yet avengers don't use STR for any of their powers or class features--butt you don't care because avenger powers suck anyway.
I mentioned half-elf avenger several times. You know why? Because half-elves have a feat in this book called Versatile Master, which changes the power they selected with Half-Elf Dilennte into an At-Will. And the power is going to be Twin Strike or Dual Strike. So what you have right now is:
A character that picked a race that is ENTIRELY unsuited for their base class and also picked a stat array that doesn't match their class at all--because they're half-elves there's no reason for them not to pick up chainmail armor eventually.
But you know what? It's okay, because you're using Oath of Enmity on Twin/Dual Strike, which will still ensure that you do more damage than any other Avenger power you will ever pick. And hey, since you have no use for any of your avenger encounter or daily attack powers anymore, why bother keeping any of them? You should pick some class (like fighter or ranger) and do as much power swapping as you can for powers that you WILL use. Fighter and ranger have a bunch of encounter attack powers that don't use standard actions and also have a nice selection of multi-attack/stance dailies.
But since you can't swap out everything, you go Eternal Seeker to finish your trade. By level 29, you have something like Follow-Up Blow, Quicksilver Stance, and Sudden Assault as your daily powers and Rain of Blows (from Reserve Manuever), Storm of Blades, Cloak of Thorns, Trip-Up and Hurricane of Blades as your encounter powers.
But you have Oath of Enmity now and you also have Weapon Mastery. So it's not only okay, but you are the fucking man. Even the Ranger and Fighter bow down in front of you and suck on your cock.
And all you had to do was completely ignore every facet of your class, from the light armor to the stat array to the feats to the powers and just focus on one feature.
And that, my friends, is why multiclassing will never be balanced. Isn't 4th Edition awesome?