The evolution process is split into 6 star ranks, these are represented by 1-5 stars 
and an absolute star 
at rank 6.
To Evolve heroes you need Soul Stones
Soul Stones[]
In order to get new or evolve your existing Heroes, Titans, and Pets you need to collect the corresponding Soul Stones.
After reaching the necessary amount of Soul Stones the evolution process costs Gold but will increase the Stats per level, e.g: Galahad gets 4 Strength, 3 Intelligence, and 3 Agility per level at star rank 1 but 20 Strength, 13 Intelligence, and 17 Agility per level at star rank 6 / absolute star. Therefore the star rank gets more and more important the higher the level of your Heroes, Titans, and Pets is.
The most difficult Hero to evolve is Jet because his Soul Stones can only be obtained in the Soul Shop with Soul Coins. These can be traded in for excess Hero Soul Stones at 1 Soul Stone to 100 Soul Coin. The price for 1 Jet Soul Stone is 1,000 Soul Coin, or 10 non-Jet Soul Stones, making him 10 times more expensive than any other hero to evolve to absolute star.
The Easiest Hero to evolve is Cleaver only If you get him ,
Evolution cost found on the Soul Stones page.
Artifacts[]
Artifacts, Titan Artifacts, and Elemental Spirits also have an evolution level, they require the corresponding fragment to increase the evolution rank but otherwise they exactly the same.
Evolution cost and further details are found on the corresponding pages.
Gallery[]
