9 Soul Stones can be opened in 1 go and, if 9 are opened, there is a chance of a slot being highlighted to indicate part of the code for the Ancient Secret.
Soul Stones come in 3 varieties:
- Rare (1*-3*)
- Epic (3*-5*)
- Mystic (5*)
It is currently considered that Epic Soul Stones have a very small chance to give a 4* unit (<2.5%). Therefore, buying Soul Stones should be considered wisely.
Rare Soul Stones can be obtained from missions, arcane portal, chests won from sieges and the guild shop. They can be upgraded in the Hall of Souls to Epic by gambling Soul Shards similarly to Traits. Upgraded Soul Stones can have bonuses that are rewarded when opened. Bonuses can be energy, siege stones, ressurection potion and gold keys.
Epic Soul Stones can be obtained from Map Bosses, Tree of Life￼, Arcane Portal, Guild Shop or randomly in missions. The chance of obtaining an Epic Soul Stone from a mission increases with Castle Level.
Mystic Soul Stones can be obtained from the Arcane Portal or bought from the Guild Shop.