He can pretty much do everything Tifa can and more. He possesses the speed to hit relativistic effects(My Final Heaven), and the strength to crack open the crust of the Earth with a punch(Burning Rave). Not to even mention his, apparent, hadouken (Meteor Barret). Or his sheer damage potential in the "Armageddon Fist," which, for pure numbers, can easily outdamage both Cloud's Omnislash and Squall's Lionheart.
Which is more impressive in your opinion (while, of course, ignoring the 'prettiness' of the 3D over 2D)? Well, I suppose it may be a bit subjective.
However, we can say with certainty that Sabin can access his blitzes far more easily than Tifa's limit or Zell's duel. Next in order of ease of access would be Tifa, who merely must take enough damage, and lastly is Zell who must be at low hit points.
If we were allowing spells, Zell would jump up to second due to aura, though that still doesn't beat out Sabin being able to blitz every single round.
Is that balanced by Zell's ability to do a flurry of Duels at a time, though?
Could Zell last through a single Bum Rush (Phantom Rush)? Could Sabin last through a My Final Heaven or an Armageddon Fist routine? Who could pull off which first?
If i remember properly (havent played VI since i was like 9) there was a part where sabin lifted up a huge rock door for the team, which should be well over 5 tons.
Sabin can shoots big beams, fire like 50 flaming bolts the size of himself, he can heal himself, he also has a power that unleashes like ultima, Zell wont even get near him and even if he did, Sabin can probably take him.
Zell wouldnt be able to get close to him, and if he did Sabin would still
I dunno about a huge rock door off the top of my head, but he grabs a huge falling girder after you beat Kefka, and right after you get to the World of Ruin, he supports a large mansion in Tzen.
Anywho, enumerating the blitzes;
Pummel/Raging Fist - Meh. A regular 'Fight' command does about as well at high levels.
Aurabolt/Cannon - HADOUKEN! Sabin's big advantage - range.
Suplex/Meteor Strike - Zell and Tifa both have this move as well.
Fire Dance/Rising Phoenix - How this is martial arts related, I don't know, but the image of dozens of Sabin's hitting the enemy is pretty sweet. This is actually weaker than Aura Cannon, if I recall correctly, but it's an area attack, making it much harder to dodge.
Mantra/Chakra - Worthless. It doesn't affect Sabin, and he has no allies to use it on.
Air Blade/Razor Gale - Oh ho, more powerful than Auracannon, but has the area attack like Rising Phoenix. This is probably Sabin's best chance.
Spiraler/Soul Spiral - See Mantra/Chakra. Except now it's also prepackaged with suicide.
Bum Rush/Phantom Rush - Speedblitz. Awesome technique, could likely take out Tifa, but probably not Zell, who can move at speeds eclipsing these.
I'd say Sabin's best chance at winning here would be the Razor Gale technique, but he'd have to get it off before Zell got a chance to do a Duel. I'd also say that Sabin's variety, range, and speed advantages assure his placement over Tifa, and Zell's sheer power assures his.
I'm still not entirely sure who I think would win between Sabin and Zell, though.