To help people relate to a metric, I’ve computed the number of “Sonyas” for each 4* and 5* hero. A ranking of 1.00 Sonya says that one special attack from Sonya will kill the hero (ignoring the color weak/strong, assuming both heroes are fully leveled, ignoring troops, buffs, attack/defense bonuses on raid defense, etc.). The higher a hero’s Sonya’s are, the more durable they are.
Here are the hero rosters, listed from most durable to least, and the “Sonyas” for each. The new characters for the summer event are included with their preliminary stats from beta:
Legendary Heroes (5*):
Epic Heroes (4*):