And no, Soul Hax isn't exclusive to that at all. Status Effects and Petrification work on spirits, and he can just outright destroy souls with his own.
Do show how. Petrification is a form of Transmutation. Why does it matter that those 2 powers work against spirits? The last sentence is just NPI.
- Dimensional Vanish: Regen
A win for Magolor by the time he does so, Sephy's going to get f*cked/separated and blown away by Spatial Manipulation that harms others who can resist it on interstellar scale by warping all of it into them.
- Black Holes: Sephiroth resists gravity and can dodge/teleport
Sephy doesn't resist it on the scale Magolor has it, who can harm others with resistance to it on an interstellar scale with a black hole that, again, was warping all that into them. "Can dodge/teleport" seems like just redundancy when Magolor can make the move as fast as any other attack, or miss it intentionally or accidentally and later try to grab Sephy to throw him in it/near it.
- Friend Hearts: Literally nothing stops him from dodging, blocking the attack via barriers, teleportation, etc.
Teleportation works. Dodging can be dangerous, canonically the thing pretty much has around itself the hitbox of Marth's grab in Melee if you know what I mean, and considering that it's spammable Magolor may be already starting to throw another when Sephy finishes to dodge, or Magolor does something else. Idk why a barrier would work against something that goes inside stuff. Potentially, there exists the chance that Sephy may not even know if the pink heart-shaped thing will be a threat in a way that slows a bit any potential defensive maneuver, he could even try to grab it to see it.
- Reading his memories and mind
Telepathy is a form of Mind Manip, which he resist. Also that doesn't really do much.
That doesn't do much.
- Sending him immediately to his last legs with Heartless Angel
Between this, 1 attack more to kill him and Ghost form to maybe come back, it's still a disadvantage but he'll be surving for quite a while to not feel like using a Friend Heart. The first time he's on his last legs, if it's not the last, can easily make him feel like doing so, or he could warp himself out of that dimension for a while to make his regen heal him to variable results or spam teleportation.
Also isn't the Heartless Angel a literal angel descending to do that? If so then that's a terrible idea, you never have to summon anything against Friend Heart users, temporary summon or otherwise, a common thing to do against it is to just steal it as an ally and have it work against whoever summoned it with now more enemies that can use Friend Hearts each and can heal each other.
If you want to scale people to other people, Dissidia exists where he's fought all manner of opponents, including other mages with similar abilities to magalor like Kefka, Exdeath, Shantotto, et cetera, and kept up with and kept aware of the exact same things.
I didn't just "scale people to other people", I pointed out canon stuff and non-canon stuff only because it's stated, and we have annotated in a blog, that it works to show what the characters can actually do. Dissidia isn't canon in a way that we can say that Sephy has experience against those characters, heck we shouldn't even use Dissidia in the way we do but eh.
If you're not voting then why are you arguing for Magolor on a VS thread. At least be upfront about it and put a vote down.
Everything you said before I understand, this bit has a terrible logic to it. Anyone can argue advantages, disadvantages, if they believe something's correct or not in Vsthreads without being sure enough (or care enough) to give a vote. Maybe Sephy wins, I wouldn't mind it and I would have maybe contributed in clarifying some things for the thread, contributions like it can exist.