Asmadeo is a pure killing machine, on my solo he is level 52 now, has 3744hp, 107 points defence, 87 % resist to melee, 80% to magic and 55% to Fire and poison....he had no mercy with a stack of 20 Black Dragons, only massive Level 3 or Level 4 stacks hurt him so much that it is dangerous. Level 5 units are a piece of cake.
I will never play with him and a full army, he alone is so powerful that it seems to make no fun if you have him and 5 other units.
It is correct, he can heal himself with 3 points in Necromancer.
And the Skill with the ability to heal living units transfers only HP von one friendly living unit to a other friendly unit. But i have only one point in it, if the skill can damage enemys and heal your units later it should be good, but on my solo it is not a priority because i had no other units