The elf is an old hero who fought demons, the other party is a phenomenon that assumed a body of a girl with the power akin to a demon lord, connect the dots.
Didn’t say that he’ll do it unprovoked but it’s on the table.
Bel papa is an anomaly, no one can just pluck a phenomenon from a forest and raise them as a normal human child. Without him, who know how will it turn out.