Soul Altar
At the Soul Altar, you can rollback, reset or sacrifice heroes.

Hero Rollback
This brings your hero back to level 1, and returns all the materials consumed. Only heroes that are 3 stars or above can be rolled back. Each rollback costs 20 gems.

Stars Reset
This returns resources used in leveling up, advancing and awakening. Awakening materials are returned in the form of random hero fragments. Only heroes that are 6 stars or above can be reset.

Hero Sacrifice
Sacrificed heroes are converted to Soulstones, which can be used to purchase powerful heroes in the Soul Store. Resources, equipment and runes used in upgrading the hero will be returned. You may also enable auto-sacrifice to automatically sacrifice 3-Star heroes to get Soulstones.