Cast Storm King's Thunder by paying {R}{R}{R} plus an additional {1} for every twenty life your opponents collectively have, copying the next instant or sorcery spell you cast that many times.
Cast Scheming Symmetry by paying {B}.
Storm King's Thunder triggers, copying Scheming Symmetry at least once.
Resolve a Scheming Symmetry, causing two opponents to search their library for a card, and then shuffle their libraries and put the card on top of it.
Ob Nixilis triggers for each opponent who searched their library, causing them to lose ten life.
Repeat from step 4 for each remaining Scheming Symmetry.

Each opponent loses the game

Near-infinite lifeloss

Ob Nixilis, Unshackled

Storm King's Thunder

Scheming Symmetry

Cast Seasons Past by paying {4}{G}{G}, returning Time Warp, Scheming Symmetry, and any number of cards with different mana costs to your hand and putting Seasons Past on the bottom of your library.
Cast Scheming Symmetry by paying {B}, putting Seasons Past on top of your library and allowing target player to put the card of their choice in their library on top of their library.
Cast Time Warp by paying {3}{U}{U}, granting you an extra turn.
In the draw step of your next extra turn, draw Seasons Past.
Repeat each turn.

Infinite turns

Lock

Skip your draw steps

Seasons Past

Time Warp

Cast Seasons Past by paying {4}{G}{G}, returning Temporal Manipulation, Scheming Symmetry, and any number of cards with different mana costs to your hand and putting Seasons Past on the bottom of your library.
Cast Scheming Symmetry by paying {B}, putting Seasons Past on top of your library and allowing target player to put the card of their choice in their library on top of their library.
Cast Temporal Manipulation by paying {3}{U}{U}, granting you an extra turn.
In the draw step of your next extra turn, draw Seasons Past.
Repeat each turn.

Temporal Manipulation

Cast Seasons Past by paying {4}{G}{G}, returning Capture of Jingzhou, Scheming Symmetry, and any number of cards with different mana costs to your hand and putting Seasons Past on the bottom of your library.
Cast Scheming Symmetry by paying {B}, putting Seasons Past on top of your library and allowing target player to put the card of their choice in their library on top of their library.
Cast Capture of Jingzhou by paying {3}{U}{U}, granting you an extra turn.
In the draw step of your next extra turn, draw Seasons Past.
Repeat each turn.

Capture of Jingzhou

Cast Micromancer by paying {3}{U}.
Micromancer enters the battlefield and triggers, searching your library for Dark Ritual and putting it into your hand.
Cast Dark Ritual by paying {B}.
Displacer Kitten triggers, blinking Micromancer.
Micromancer triggers, searching your library for Scheming Symmetry and putting it into your hand.
Dark Ritual resolves, adding {B}{B}{B} and going to the bottom of your library.
Cast Scheming Symmetry by paying {B}, targeting any two players.
Displacer Kitten triggers, blinking Micromancer.
Micromancer triggers, searching your library for Dark Ritual and putting it into your hand.
Scheming Symmetry triggers, exiling a card from each targeted opponent's library due to Opposition Agent's effect, and going to the bottom of your library.
Repeat from step 3.

Exile each opponent's library

Infinite black mana

Infinite ETB

Infinite LTB

Infinite magecraft triggers

Infinite storm count

Wheel of Sun and Moon

Displacer Kitten

Micromancer

Opposition Agent

Dark Ritual

Cast Seasons Past by paying {4}{G}{G}, returning Walk the Aeons, Scheming Symmetry, and any number of cards with different mana costs to your hand and putting Seasons Past on the bottom of your library.
Cast Scheming Symmetry by paying {B}, putting Seasons Past on top of your library and allowing target player to put the card of their choice in their library on top of their library.
Cast Walk the Aeons by paying {4}{U}{U}, granting you an extra turn.
In the draw step of your next extra turn, draw Seasons Past.
Repeat each turn.

Walk the Aeons

Combos with "Scheming Symmetry"