how do i get my skills past level 10?

hmn i thought at level 10 you master the skill ... hmn ...

if you put your cursor to the mastered skill.. you'll see theres a description for its lvl 11.. granadocafe's info says skills go up to lvl12..

maybe skill rings.. cause my for musk i have 2 bird fall rings so it's level 12.

Yeah I think it's for 2 rings. I don't think anyone has a buff that buffs skill levels. So far the only ring I found is for Esperanza.