Would you like to play as a Necromancer with the ability to upgrade Vampires?

go ahead and try it. preferably not with a level 1 hero, but with someone who's at least somewhat leveled up. Vampires and 6 units, put them in the first stack, for example. First, use the Time Stop spell, and then position yourself in a corner of the map. Two packs of griffins will fly over and attack them. You'll come out of there with losses of 6 units and 4 angels.