As a healing Hero, he does not do damage of any kind. Similar to Medics, he will heal your troops.
As a Hero, she does not require time or Gold to train. If she is defeated in battle, she will reappear in the Hero Hut after the battle, fully healed and ready to fight again.
His Hero Perk is Galvanizing Presence, which reduces incoming damage of troops he heals for a short period of time.
Hero Abilities
Similar to Gunboat Weaponry, Hero Abilities can be used during battle at the cost of Gunboat energy. Your hero can only have one ability active in a battle. The ability can be fired more than once, but the energy cost increases each time. The following are the three abilities available to Dr. Kavan. Click one to read more about it.