Board Thread:General Discussion/@comment-30330716-20170223150337/@comment-13682699-20170225195851

The only known way he could absorb Jerry's soul is if he had the 6 human souls granting him the power to absorb them without killing them first (and risk losing the soul as it disappears instantly once the monster dies). After all, it did say that it would take an unusually large amount of power to separate a monster soul from a living monster. It may be debatable if he could do it with just one human soul since having just one human soul is already a massive upgrade in power, but it was shown specifically in game that he could do so with the combined might of 6 human souls.