N-Wild, R-Wild and SR-Wild can only get Cards to level 100.
N-Gacha, (R-Gacha and SR-Gacha) , Ex-Wild, Kurito and and spins can take Cards to level highrt than 100 if you unlock levels higher than 100.
I would suggest only to use Ex-Wild on SR-Girls that can not gain Ex-level froms spins or N-Gacha

Thanks for the response. Wasn't really intending to use the ex wilds so quickly (I'm a hoarder. Is is that man whore? I get them confused). Just wanted to get an idea of when the pluses may stop.