Question with skill mutation and Skill Inheritance

I'm trying to kill the Reaper at the beginning of the game, I'm watching a video to help me know how to use mutations, the strategy consists in mutate the ability of any persona until reaching tier 7 with Repel Slash / Strike / Pierce, I have a slime all the skills in tier 6 trying to make them become repel in tier 7, but I'm really in doubt if any persona can actually inherit these skills and learn them by mutating