I think I have a silly infinite combo here that I'd like to run by the rules crowd here to see if I'm missing anything.

I have the following in play: Niv-Mizzet, Parun, Archmage Ascension with 6 counters on it, and Possibility Storm.
I have Pact of the Titan in my hand.
I have Beacon of Destruction in my library somewhere.


1)Cast Pact
2)Put Niv draw trigger on the stack
3)Put Possibility Storm trigger on the stack
4)Resolve Possibility storm trigger

5a)I find an instant I want to cast off of Possibility Storm, cast it
6a)Put Niv draw trigger on the stack
7a)Resolve Niv draw trigger from PS spell, replace the draw with a tutor thanks to Archmage Ascension and tutor up Pact
8a)Return to step 1 (still have Niv draw trigger from step 2 on the stack, don't let it resolve)

5b)I find an instant I don't want to or can't cast (such as counterspell), I let it go to bottom of the library
6b)I let the Niv draw trigger from step 2 resolve, replace the draw with a tutor thanks to Archmage Ascension and tutor up Pact
7b)Return to step 1

Among the spells I cast in step 5a) is Beacon of Destruction. Since it puts itself back into the library I can keep casting it off of Possibility Storm triggers from the Pact.

The 5b) route can eventually be done away with as several of the spells I cast in 5a) will be card draw spells (Brainstorm, Chemister's insight, etc.), which I replace to be tutors thanks to Archmage Ascension, to pull all of the problematic instants out of the deck eventually leaving the deck with only Pact and Beacon as far as instants are concerned.

Beacon of Destruction is the most direct way of winning the game, though it is worth noting that Nexus of Fate also works as a win condition as I will eventually take all the turns and end up killing people with Niv (or whatever other method I happen to find). Please note that Pact of the Titan never resolves during these loops so I don't have to pay a bazillion mana on my next upkeep to stop from losing the game.

Pact can be replaced with an already in play Omniscience to use sorceries in this loop, not just instants. While technically I can't ever resolve the last spell of each card type from the deck unless I have something that shuffles itself back in (a drawback of Possibility Storm), I'm sure I can find some way to win with all but one of each spell type being cast from my deck. Or, actually, Beacon of Tomorrows can be the payoff spell for this sorceries loop.

Does this janktastic combo work the way I'm describing it?
Is there anything problematic you can see with this loop?

Edit: Step 7.5a)Let the spell cast off Possibility Storm resolve

I don't see any part of this that wouldn't work.