Fascinating & Disgusting
To Michael's great misfortune, using his Soultraits didn't help him much. He was still unable to cut Selena.
In the first place, it was much harder to maintain the Curse Fusion and actively utilize his curse power, coursing it through his body while using the power of the Cursed Seals, the Serpent Seals, and the Major Seals while also properly utilizing the batch of his Soultraits.
Michael spent much more time than intended in learning to combine all his powers and abilities to increase his combat prowess. Unfortunately, Selena wasn't nice enough to spare him. If anything, the Nest Leader intensified her training, just as promised. That was both a great misfortune for his body since Selene didn't hold back, breaking his bones and tearing parts of his body part, and a great fortune because he was forced to give his utmost at all times.