Let me cope with my headcanon:
Magatsu died as a girl.
We don't know how each (human) possession affects its user mentally. From what I can gather, Magatsu only possessed three humans: the Leader, Lili, and Alicia. Cmiiw.
It’s possible that after possessing Lili—the first girl we witnessed being possessed—they might’ve started to develop some feelings other than an abhorrence of the world toward Uncle, perhaps an adoration stemming from rivalry.
Ultimately, the last girl they possessed was Alicia, who—as we all would've guessed—harbors romantic feelings toward Uncle. This could've twisted what was once rivalry into adoration, and then into love.
Either that or they're just a massive troll.
Still, I hope they were indeed born a girl, despite their masculine-sounding name.
Rest well, Magatsu Kotononushi. Your epic shall echo through Granbahamal for eons to come, ever scaring misbehaving children.
