Wait wait okay so Mineru's ability is she can seperate her soul from her body and put that soul in something else. I believe in game she calls it her spirit but soul is like the same thing. Also spirit sounds more 'mystical' and soul might have religious context to it? Whatever. The stones amplify the holders already present power, not giving them 'new' ones, meaning she already had some power relating to spirit magic.

Two questions.

One, what was the extent of her power BEFORE she got the stone? In the scene she describes it as the stone gave her the ability to take her soul out of her body, not like she always had the ability to do that.

Two, if she can do that, why couldn't she separate Ganon's spirit from his body as a way to stall for time or temporarily stop his rampage?

It still doesn't make sense to me that Rarau, the light guy, was able to put Ganon in a stasis when Sonia's thing was time. Thou with Ganon killing Sonia and stealing her stone that couldn't be done. But it felt like, a kinda crappy way to go about that. The whole scene felt, not planned well. It felt like a first draft they went with instead of really dissecting the possibilities and making a more compelling and imo, more 'logical makes sense' of a story. If Sonia wasn't used as a sacrificial lamb for the story, SHE could have used her time powers to stall+stasis Ganon. She could have used her time powers to stall the malice infecting Link's arm, slowing it but never fully able to stop it due to her weakened power from keeping a lock on Ganon all these years and giving us the same reason to get the orbs to purify Link's arm.

This could also serve as a mirror back to Zelda's plight from BotW, stalling the big bad (she wasn't using time powers but still) but her power waning, unable to fully end it, just slow it down. Fighting the same foe, failing, and stalling, relying on the hero to finish business.

However, I feel like part of the reason Rarau was chosen to stop Ganon and give Link his arm was that he's Zonai, he's new, and the developers wanted to push that rather than the ancient Hylians. After all they did give us *too much of the Zonai and also still not enough. Even thou Rarau ends up playing such a small part in Link's encounters and is like, never seen again after the tutorial area then once more at the very anti climatic ending for Zelda.

Incase you couldn't tell, I have NOT finished the game, I probably never will and I've only spent 45 hours on it then never picked it up. 5 of those hours was spent on the tutorial sky island (I messed up so badly my first time that I *had to start over). I have also not seen many ending scenes so maybe there was a legit reason Mineru couldn't trap Ganon's soul but with the crappy writing of this game, I wouldn't be surprised if it was some dumb reason.