Board Thread:Questions and Answers/@comment-25270263-20140805232252/@comment-25260362-20140826213113

Kirakagomine wrote: The only other way you can level up a daemons skill is by fusing the same exact daemon together.

I'd like to precise something once again. You can level up a daemon's skill by fusing another daemon with the same skill (meaning same skill name and same skill effect). Doesn't have to be the same daemon :p for exemple, Kiri can be maxed with Kotetsus or transmigrated Barbettas. Well, sadly, event daemons usually have a unique skill (meaning that nobody else has the same skill) so unless you got their magatama or somehow got a replicate through invitation reward (if the daemons is a 5*), then yeah, you can't max their skill.

Also, I'd like to note that you can get a 100% chance to level up a skill if the fused daemon is maxed. For example, if you wanna get a 100% chance to level up Kiri's skill, you'd have to get a maxed Kotetsu/Transmigrated Barbetta.