The most powerful warrior.

I don't know if phoenixes are reborn after being killed by the "hand of death" of the Harbingers, I don't think so... and as for the Black Dragon, it also dies from the Harbingers' attacks, folding its wings... The strongest one was in Heroes of Might and Magic IV, the Dragon King... Well, if we're talking about Heroes of Might and Magic V, in my opinion, the most powerful creatures are the Archangels... (although I don't really like them...).