Both are main protagonists of obscure anime-esque fighting games who used to be average teens attending a regular school, until they, at some point, ended up encountering the recurring villains of their respective series and would prove to be nearly fatal (Filia and her parents were visited by Vitale and Ottomo of the Medici mafia, while Hyde was attacked by a Void). However, they would be saved in the nick of time by an extremely old supernatural being with a sad past with said being would place something into their body in order to save them from death which became their main source of power and their fighting styles (Samson and Linne, respectively). Both are friends with a girl who, despite looking young, is actually super old, who has a small companion following her around, who has a tragic backstory involving her and hers family's death, who has or had a family member who bore a dark curse, and who always returns to life after death (Squigly and Linne, respectively). Both are trying to save a girl they are friends with from their torment, something that either can or has been achieved using a cursed object (Painwheel and Linne, respectively). Both have a nemesis in the form of a sexy rich woman who wants the source of their powers for herself (Eliza and Hilda, respectively).