Activate all mana-producing lands you control by tapping them, adding at least {U}{U}{U}{U}{R}.
Cast Turnabout by paying {U}{U}.
If you have fewer than three experience counters, Mizzix of the Izmagnus triggers, causing you to get an experience counter.
Resolve Turnabout, untapping all lands you control.
Cast Mystic Retrieval by paying {U}, returning Turnabout from your graveyard to your hand.
Cast Mystic Retrieval from your graveyard for its flashback cost by paying {R}, returning Runic Repetition from your graveyard to your hand and exiling Mystic Retrieval.
Cast Runic Repetition by paying {U}, returning Mystic Retrieval from exile to your hand.
Repeat.
If lands you control can tap to produce at least {1}{U}{U}{U}{U}{R}, this combo nets infinite mana.

Infinite magecraft triggers

Infinite mana permanents you control can produce

Infinite storm count

Mizzix of the Izmagnus

Mystic Retrieval

Runic Repetition

Turnabout

Cast Time Warp by paying {3}{U}{U}, causing you to take an extra turn after this one.
Cast Mystic Retrieval by paying {3}{U}, returning Runic Repetition to your hand from your graveyard.
Cast Mystic Retrieval from your graveyard for its flashback cost by paying {2}{R}, returning Time Warp from your graveyard to your hand and exiling Mystic Retrieval.
Cast Runic Repetition by paying {2}{U}, returning Mystic Retrieval from exile to your hand.
Repeat each turn.

Infinite turns

Lock

Time Warp

Cast Apex of Power by paying {R}{R}{R}, exiling the top seven cards of your library with the ability to cast them until end of turn, and adding either ten {U} or ten {R}.
Cast Mystic Retrieval by paying {U}, returning Apex of Power from your graveyard to your hand.
Cast Mystic Retrieval from your graveyard for its flashback cost by paying {R}, returning Runic Repetition from your graveyard to your hand and exiling Mystic Retrieval.
Cast Runic Repetition by paying {U}, returning Mystic Retrieval from exile to your hand.
Repeat.

Cast all spells in your library

Infinite colored mana

Vadrik, Astral Archmage

Apex of Power

Activate all mana-producing lands you control by tapping them, adding at least {U}{U}{U}{U}{R}.
Cast Turnabout by paying {U}{U}, untapping all lands you control.
Cast Mystic Retrieval by paying {U}, returning Turnabout from your graveyard to your hand.
Cast Mystic Retrieval from your graveyard for its flashback cost by paying {R}, returning Runic Repetition from your graveyard to your hand and exiling Mystic Retrieval.
Cast Runic Repetition by paying {U}, returning Mystic Retrieval from exile to your hand.
Repeat.
If lands you control can tap to produce at least {1}{U}{U}{U}{U}{R}, this combo nets infinite mana.

Cast Apex of Power by paying at most {4}{R}{R}{R}.
If you have fewer than ten experience counters, Mizzix of the Izmagnus triggers, causing you to get an experience counter.
Resolve Apex of Power, exiling the top seven cards of your library with the ability to cast them until end of turn, and adding either ten {U} or ten {R}.
Cast Mystic Retrieval by paying {U}, returning Apex of Power from your graveyard to your hand.
Cast Mystic Retrieval from your graveyard for its flashback cost by paying {R}, returning Runic Repetition from your graveyard to your hand and exiling Mystic Retrieval.
Cast Runic Repetition by paying {U}, returning Mystic Retrieval from exile to your hand.
Repeat.

Cast any instant or sorcery spell with flashback by paying its cost.
Eye of the Storm triggers, exiling that card, then allowing you to cast copies of all spells exiled with Eye of the Storm.
Resolve the Seething Song copy, adding {R}{R}{R}{R}{R}.
Resolve the Runic Repetition copy, returning the card you cast in step 1 from exile to your hand.
Resolve all other spell copies.
Repeat.

Combos with "Runic Repetition"