Incubi are simply great, they are the Aspect Warriors Eldar wish they had. And since they are battle brothers, it would be easy to fit them into your Eldar list. I like to run mine in a unit of 3 + the Klaivex in a Venom. Doesn't sound much?
That Klaivex is one of the most powerful Sargent in the game and he eats an Exarch for Breakfast.
Ws 6 A 3
AP 2 with Rampage base. Due to power from pain, i have had a single Klaivex (his buddies died) charge a 6 Man
tac squad late game. Due to power from pain he had 8 (3+Rage+D3 Rampage) attacks at Strength 5, he slaughtered 5 of them on the charge.
So yeah, using Incubi would seem to work for the purpose you'd want. Maybe model them based off of the old Incubi models i'm sure you could get off Ebay? Replace the tip with those Spiked Ball chains and it they look suitably badass.