Dire Avengers is a basic infantry squad that the Eldar can produce.
This squad can be considered a direct upgrade from the Guardian Defenders, other than the specialized upgrade this squad can receive from a Soul Shrine.
This squad is only effective against Infantry and Heavy Infantry, but if the squad receives a Brightlance Grav Platform or a D-Cannon Grav Platform, they can be effective against armor.
Vengeful Persistence Research - found in Aspect Portal, increases ability range, and recharge rates of those abilities for the squad, as well as increasing the damage output of Dire Avengers, and their Exarch especially.
Aside from this, this squad receives wargear benefits like all other Eldar squads.