Is it possible to defeat 1000 Archangels with just one Imp?

You can use Necromancers – even with just 1 Imp or 1 Skeleton))) The main thing is to have a Berserk spell handy and the Spiritual Bond skill. In other cases, I doubt the hero will have enough mana. And the hero should be at a higher level – so that the Berserk spell lasts at least 3 turns with a maximum of 2 units.