the strongest, unupgraded unit at level 7.

I voted for the angel... because he is actually stronger and more useful. Dirty Player, as for the duels between the devil and the angel, download a combat simulator for the third Heroes game and see for yourself. Out of 100 one-on-one battles, the angel wins 98-100 times, and the devil, accordingly, 0-2 times. In a battle of 10 versus 10, the angel wins all 100 battles. There's no point in watching further... I think the program isn't cheating.