Anyway, so
With or without the paralysis or time stop, the fight is going to be The End sitting in one place getting pounded on by Asriel while firing lasers back.
True Reset is over the hax limit, and I'm guessing The End's reality-warping is in the same situation.
We know that Asriel can hit The End's avatar through its incorporeality.
Asriel has a lot of hax with all the monster souls in him, but most of them are just other ways to attack.
The End also has a lot of hax which basically just boil down to 'attack good', it can suck out the and transform souls of those it has a contract with, but Asriel has no reason to make a contract with The End so he is safe.
Because of The End's acausality, regular Resets won't do anything other than reset both of their physical statuses. The End would keep its memories so it might even be beneficial to it if Asriel tries to Reset since both would start the battle fresh but with more knowledge.
The End can talk to minds from other dimensions and has super intelligence, it could easily talk to all the souls in Asriel.
The souls in the fight in-game are all speaking and acting as themselves, though they don't remember Frisk, so I believe if The End were to reach out to them they would be able to talk and make deals.
The End is very persuasive, it's used to making deals and can be very generous with its terms. The deal it offers in-game borders on game-breaking with how powerful it is while it is active, and it can make the deal as long or as short as it wants.
I think if it had the chance to talk to the souls, it could learn exactly what each soul wants and what would make them agree to a pact. If Asriel tries to reset, The End would remember what it learned and could just offer the deal again to the fresh soul even faster. If The End gets to make a deal with all of the souls, or at least the human souls, then it could reap them and depower Asriel. All it would take is one human soul, (or all the monster souls but that is more unlikely), and Asriel would be forced back into Photoshop Flowey form and be much much weaker. Then The End could simply zap Flowey into dust.
Asriel doesn't have any hax instant win conditions like The End that I can see, but I do think that Asriel would win a straight punch-for-punch fight. The End just sits in one place and takes all punishment sent toward it, and it relies on its shields, large defense, and massive health to tank damage in game. Given that stats are equal its defense is the same as Asriel's, so that doesn't really matter, and health might be equalized but I'm not sure. Its shields are regenerating, so it will take some time, but in the end, Asriel just attacks faster than The End.
But, Asriel actually moves and dodges, and while The End's lasers are practically instant they do occasionally miss against fast-moving targets like Corvette class ships.
