Crest forging can be accessed through your Warehouse or the Heroes Altar in the appropriate ‘Forge’ tab.
Crest forging is a process where you forge 2 Crests that are the same level to form a new crest of the same level. You can use any 2 Crests from any slots including identical Crests. The product of the forge is completely random and is not influenced in any way by the ingredient Crests. The output Crest is the same level as the 2 input Crests. The price of the forge is always a cost of Blue Crystals and increases depending on the level of the Crests involved.
The likelihood of forging a Mythic crest is rarer than a Rare crest is rarer than a Ordinary Crest regardless of what the input crests are.
Level 1 Crests cost 15000
Level 2 Crests Cost 30000