TL;DR
Heals all allies for a percentage of their max health, converts overhealing into shields, and cleanses debuffs.
Tufty Ears utters loud blessings and restores 20% of the max health of all allied heroes, up to 20% of Tufty Ears' max health. Any overhealed health is converted into a shield that lasts for 5 seconds.
Lv 6 The health recovered by allied heroes is increased to 25% of their max health, without exceeding 25% of Tufty Ears' max health.
Lv 12 Tufty Ears receives more beast energy points per second.
Lv 18 Hallowed Sigh can also remove debuffs received by allied heroes.