I don't know where to post this exactly but since it's regarding the "final boss", i guess it's spoiler territory. I remember the 1st time i battled lusahilego and the very first pokemon made me terrified. Why? Because it was a already buffed with cosmic power clefable that keeps healing. I had no taunt or stat boosting moves. When i burned her and saw no damage then i remembered, "oh, no, she has magic guard". And then i thought the worst would happen. What if this exact clefable had stored power? Of course, she had metronome instead so i was relieved. But think about it, if your team wasn't overleveld, what could you really do to her? I guess taunting is the best option because without it, she just buffs, heals and has enough power to kill any non dark type you have in one shot. You could put alolan muk against her but she has moonblast so you won't resist it. I think stored power on that clefable would turn the battle difficulty up a notch and it would at least take advantage of that initial boost she has to her sp. def. 3 cosmic powers later and she has a 160 special psychic move with 100% acc. And she keeps healing too. I really thought i was gonna lose that battle on her first pokemon.
Also, a side note, why the hell does milotic get the attack boost and not bewear? if milotic got the defense boost that would make so much more sense. Weird choice.