Hilda is one of a group of Puyopuyo Quest characters called the "Accursed Knights". The members have gained powerful weapons, but at the cost of (mostly annoying) curses. Hilda got a powerful sword, but is cursed to be unable to keep herself from laughing, while she is a naturally serious person.

Stats for Hilda in her Moon Viewing Festival outfit:
https://puyonexus.com/wiki/PPQ:Otsukimi_Knight_Hilda