except for the fact that chara and frisk are both over 18 in this game, as stated by the game itself.
Both loli and shota refer to a characters appearance, not their age, which is also how “900 year old lolis” exist. I even posted the Wikipedia page where they state that it includes “young in appearance”. Him being 70 doesn’t change the fact he is a shota. It also doesn’t change the fact he is smaller than an 8 year old or that he is considered a child by the elves in overlord.