User blog comment:LordRimus/Ranked magic/@comment-27137888-20151108210638/@comment-27008999-20151110211454

I wrote "level up". And by that I meant that he would improve himself, which is something Ainz can. And you don't need named/titled skills in order to have leveled up, you might as well call them passive skills (learnt to read, write, cook). Goblin Troop cannot do anything new like cooking because they were summoned. Ainz can learn new spells (within his field and race) and swordsmanship, but only invisible "passive skills" (controlling strength in his swings) and not active skills like Cocytus.

If you count Dark Wisdom + spells that come with it as 1 level, then ok. But his fighter skills has improved and many limits from YGGDRASIL has been disabled like any form of wishes Ainz want as long as he has enough exp.