Board Thread:Wiki Discussions/@comment-77.251.31.29-20140205185320/@comment-24317058-20140206152104

Fusion is never 100% guaranteed for the armor you want.

3* can result in 4*, so that's okay

The armors have Fire/Stone and Wind/Spirit

Taking each element from 1 gives: Fire/Wind

So there is a chance for 4*, Fire/Wind which may be an Combustion Armor.

Never use your main armors though, only use spare armors