Champion Fusion is a feature that allows you to get a new Champion by fusing several available Champions.
Basics
Champion Fusion is available through your Portal. Each Champion can only be obtained by fusing the required Champions, which are shown below it.
If you have a required Champion in your collection, you’ll see a red spot in the right top corner of the Champion’s avatar.
Tap on the Champion to open the Champion selection window. If you have several Champions that meet the requirements for fusion, you can choose any of them by tapping their avatar.
Once you have selected all the required Champions, tap the “Fuse” button to get your new Champion.
Champion Fusion works like a development tree. Fuse low level Champions to get a stronger one. Then get an even more powerful Champion by fusing this Champion with other required Champions.
Fusion Mechanics
You can only fuse Champions that are of the specified Rank or higher. The Champions must also have the maximum Ascension Level for the specified Rank (or higher) and be the maximum Level for that Rank (or for their current Rank, if their current Rank is higher) to be fused.
The Rank needed for fusion depends on the Rarity of the Champion you’re trying to summon. For example, to summon a Legendary Champion, all the Champions you’re planning to fuse should have Rank 5, Level 50, and Ascension Level 5.