So I bought a Common Potion with the intention of making my Kumos Common, but when I tried to use it, it said "Invalid Combination!", which is odd since Kumos are definetely available in Common.

Perhaps Common Potions don't make your pets common after all. Oh the confusion!

So yeah, anyone know what's up with it? x

there's been a glitch with the common potion for a while now,

you could use an elixir instead?

Ah right, didn't know about that. I guess I will have to use the elixir, which is annoying since it's a lot more expensive than the Common Potion. Ah well!

I heard you could also make a ticket and have a UA turn your pet common for you.

Oh really? Thanks for letting me know, I'll do that ^^