Board Thread:Game Discussions/@comment-24.62.89.222-20140531173428/@comment-24738360-20140531173838

4* Mono's can become a 3*, 4* or, 5*

When you fuse them, they may become Duo Elements, or get fused into another Mono of those 2 types. Most people fuse Mono's with other Mono's for an increased chance for getting an Epic.