Board Thread:Character Match-Ups/@comment-26921356-20180917212003/@comment-27379005-20180917232920

Rin Okumura (Blue Exorcist) is one popular suggestion, but since there's also Rin vs Allen (D. Gray Man), Tatsumi Oga (Beelzebub) is another possibility.

Natsu is brought up too but, like the above user said, that sounds more like a DBX matchup.