Who is the character you invested the most in?

Personally for me, it has to be Acheron. I’ve never pulled for a character duplicate in a gacha game before, although she was guaranteed and it took less than 10 pulls for her e0, and also less than 10 pulls for her s1, I still lost my 50/50 on e1 and had to farm again to reach pity, she was the most I spent time on perfecting her team, relics, and sets.