Loved the DBX and that OMM, I dunno, but fast paced fights are such a delight for me. Though Sephy did lose that OMM, so less of a consolation and more of a ominous omen *insert ghastly ooooooh* I too, in a way, hope for a more fair analysis this time... But this is why I am skeptical towards Sephy vs Vergil. I mean, the Supernova is met with a lot of opposition among many people who disregard it as gameplay only or illusions, so it's rather easy to just hand wave it and make it sound convincing, which is what I think DB will do. Namely, just say it's a visual effect or "however, Sephiroth needs the Black Materia to be even able to endanger the Planet, so this sort of power can't be his own right away", and I don't think they will check the Ultimanias to see Author's word that he indeed does have that move and that power. Also, given the Supernova wasn't brought up neither for Cloud nor Tifa I see it unlikely it will come up now, especially since it would retroactively throw a wrench on the last two fights of FFVII. Not to mention they use mostly cutscene stuff and while they are using scaling more now, it's mostly still cutscene related. So I really doubt they will use the Bahamut Fury feat and scaling that puts Sephiroth at a Faster than Light speed since the cinematic took part within a battle.
To be fair, Cloud vs Link was more or less fair. I mean, Cloud did get some negatives unfairly such as being considered a dumb fighter when canon openly contradicts that, being critically weak to the Master Sword regardless of durability or the fact they ignored the Ziedrich they brought up (which massively increases defense, magic defense and also halves all elemental damage, holy included)... but, even if this hadn't been considered that way, they could have just given Link more of his items, especially since they were using a composite. Not to mention it was a Season 1 fight, they were still getting their pace down.
Can't say much about Yang vs Tifa, I barely know anything about RWBY. But it kinda goes with what I said before regarding cutscenes and ignoring gameplay: You could say she should scale to Cloud and co, and I agree, but for most people outside VS sites the tier system is a big surprise and they mostly rely on individual feats. At first you just assume they can't be FTL or capable of destroying countries because their fights never scale larger than a building or something and assume the ones of that power are the likes of Superman who can punch someone to the other side of the planet and can follow someone to the sun in an instant.
Apologies for the wall of text, will be less wordy from now on. >_>