Altina never appeared in the 1st Sen no Kiseki, so I'm putting SnK2 tag.

I really found it funny how at first, in ToCS2, Altina was a kind of closet pervert, not too unsimilar to Koharu, from Blue Archive.

Then, suddenly, in ToCS3, she was retconned to be way more immature and innocent. That was both interesting and frustrating at the same time.