The most useful monster.

OK. Here are the answers: Angel, Magic Dragon (nature), and Djinn. (This trio won't have very good morals)
Now about Black Dragons and Void Dragons. Black Dragons will be defeated, like all melee units, and considering their high cost, this is expensive, and you can't "bless" them. Of course, 10 Black Dragons will defeat 10 Void Dragons, but I would prefer to fight with a hero + 8-10 Void Dragons rather than Black Dragons.

I still don't understand how Void Dragons can cope with Black Dragons:confused: and why 10 against 10, the growth rate is different, so it should be 5 against 10:)
I completely agree that Void Dragons are a useful unit, possibly even the most useful, but they have no chance against Black Dragons, but they don't need to fight Black Dragons, Chaos has other units.
P.S. I'm not taking into account dragon strength + for example, the first strike, then everything is clear.