I self try a Asmadeo solo (Asmodean? Asmodeus? in my game he hears not if i yell him so

)
The only big problem is that if you had no unit at the start of the battle you loss befor you can summon him.
But i have a undead Skeleton on my side to start the battle and to lvlup Asmadeo with the heal undead spell.
If the undead is dead befor i can use the spell no problem, but Asmadeo is really a aggro machine, the single Skeleton is not often a target for the computer (but priests and all other good undead killer target the Skeleton in no time)