@horologium0 That's awesome. The only issues I see with Hope are 1) you are forced to wait a turn to be protected, so it's hard to win turn 1, 2) it turns on their otherwise useless creature removal killing Hope turn 1 to have their counterspell active, 3) it doesn't ALSO answer null rod/stony silence/collector ouphe, which shuts your deck down flat. Teferi is the nice all in one package that is immune to removal, bounces the "null rod" effects, stops ALL responses on your turn, and can also do things like bouncing your mox opal for that second W/R mana to go off (while drawing a card).
I'd recommend 3x ballista main and 1 in SB with main Karn if you want to be more colorless. One reason I chose Stroke as a win con is because it's blue to pitch to FoW if needed, can be fetched with mystical or scroll, so it's like having 2 more virtual win cons, and varies kills in case a sorcerous spyglass lands, naming ballista. Ballista is just a great card on its own right and can easily be a 5/5 with the absurd mana we generate naturally. It can also be cast for 2 mana to get a cheap bounce target for PO. It's the best colorless wincon I found. Ugin is a broken card, but it doesn't win on the same turn.
A couple cool things I noticed:
While deafening silence stops PO and shuts down storm cold, it does nothing to this deck but slow it (and if you are on the play, it may be a blank completely). Consider you open with land, sol ring, grim monolith, pass. Opponent plays DS. On your turn, you play land (or just use your land+mox if your mox is R/W), cast Zirda (a creature), infinite mana, cast ballista, stroke, karn -> ballista, etc. -- It ONLY stops Urza from casting more than 1 spell. If you get Urza as your only wincon in hand, you can still get a free spell or more on your opponent's turn and also your turn, which is more than enough to just grind a win.
The deck is virtually immune to blood moon. Anyone that plays me (KillerKarma) on Cockatrice knows I run a welder/moon/painter deck quite often, and blood moon is an absolute house vs 90% of Vintage. But Zirda can be cast off 1RR, so you can just infinite and cast a colorless wincon easily (or stroke off a sapphire/lotus/opal). That's an absurdly great side effect of the hybrid mana of Zirda.
The ONE big weakness of the deck is Containment Priest. It keeps Zirda in the SB. You can still win without Zirda, and between FoW and Teferi, you should be able to stop CP, but it is an available answer card, if nothing more than a speed bump.
Some cards I considered and might still try to squeeze in (for the UWg build):
Some giant tinkerbot with an activated ability
Brain Freeze (since you can just PO storm like crazy)
Kinnan, Bonder Prodigy (since it combos with basalt monolith for infinite mana too)
Kozilek, the Great Distortion
Spawnsire of Ulamog (with Emrakul, Aeons Torn in the sideboard)
*Update - I just tried some of the above cards. -1 PO (sub for Kozilek), -1 Preordain (sub for Sensei top), -1 Urza (sub for Spawnsire & -1 hurkyls in SB for Emrakul). These lead to even more broken paths. Channel into Kozilek is bonkers. Spawnsire is more castable than Urza once you've gone infinite and the Emrakul from the SB means you swing with annihilator 6 and 22 damage on the board turn 1. Just WOW. I think the genie is out of the bottle and Vintage is broken. Can't even restrict Zirda as it is a SB 1-of. They can re-restrict grim monolith, and I don't even think that matters. Would they really restict BASALT monolith too? THIS DECK IS SO NUTS!