Self heal makes sense on high attack stat heroes such as Musashi whose heal lasts for a full 5 turns.
Aegir: . . . 615 Attack - Heals 100% of dmg 3 turns - Average Mana
Musashi: 786 Attack - Heals 50% of dmg 5 turns - Fast Mana
Musashi deals decent 332% splash damage too, helps kill the enemy.
Aegir does no damage…to the enemy. He kills his flanks instead. OK, he has a +4% elemental healing link which IS a good skill, now you can run a mono blue defense team, yay.
Even poor, reviled Leonidas:
731 Attack - Heals 75% of special skill damage dealt (365%). He also cuts mana 40% too.
So, insta-heal, deals damage, controls mana…