R: Thrasios, Tevesh Szat (EDH / Commander)

Doomsday Piles:

Tevesh Pile:

Gitaxian Probe
Veil of Summer
Thassa's Oracle
Pact of Negation
Noxious Revival

Cost: UUG

Activate Tevesh, drawing git probe and veil
Cast Git probe
If a counter attempt is made, cast veil -- drawing Thoracle.
If you drew thoracle from Veil, git probe now resolves and draws pact.
Draw Thassa's Oracle, and cast it
You now have pact in hand to deal with any surprises from opponents (like Pyroblast or Hushwing Gryff)
If needed, Noxious can put Thoracle back on top and you can try again the following turn by activating Thrasios or similar.

Thrasios Pile:

Brainstorm
Thassa's Oracle
Lotus Petal
Fetchland
Fetchable land

This pile costs 5 mana after doomsday and assumes you haven't made your land drop, but most of it is colorless so we can bank on using something like cradle or culling ritual to get there. After activating Thrasios, you brainstorm and draw thoracle/land/petal and put 2 arbitrary cards back. Because your devotion is 3, you can go land, petal, fetch, thoracle and win - or just play petal and thoracle and win. If you don't need a land, you could sub Noxious Revival for protection here.

Cantrip Pile:

With any cantrip in hand, we can construct a pile that lets us use Git Probe and LED to cast Thoracle for only UU:

Brainstorm
LED
Gitaxian Probe/Ponder
Thoracle
Anything (or fetch+land instead if you have one or the other)

For this pile, we cantrip drawing Brainstorm and then cast it - drawing LED, another cantrip, and countermagic. We then play LED (protected by countermagic) and cast the cantrip, holding priority and cracking LED for Blue . Cantrip resolves and we Draw Thoracle and cast it.

Lab Man Pile:

Lion's Eye Diamond
Brainstorm
Yawgmoth's Will
Gitaxian Probe
Laboratory Maniac

This pile costs UU and requires any non-general creature. You can play it by:

Activating Tevesh
Play LED
Cast Brainstorm
Put Lab Man and Yawg Will back (Lab Man on Bottom)
Cast Git Probe, hold priority, crack LED for BBB
Draw Yawg will, play it.
Recast LED
Crack it for UUU
Cast Git probe, draw lab man
Cast Lab man
Play Brainstorm

Lab Man in-play Pile:

Lotus Petal
Brainstorm
Lion's Eye Diamond
Gitaxian Probe
Yawgmoth's Will

This pile is free - but requires you to already have lab man in play with Tevesh. To begin:

Sacrifice lab man to Tevesh
Draw petal and brainstorm
Cast brainstorm
Put back Yawg Will and any card
Cast LED
Cast Git probe, hold priority, crack LED for BBB
Draw and cast Yawg Will
Replay LED and petal
Crack LED for UUU
Cast lab man
Crack petal for U and cast brainstorm