Activate all mana-producing lands you control by tapping them, adding at least {4}{U}{R}.
Cast Turnabout by paying {2}{U}{U}.
Holding priority, activate Rootha by paying {2} and returning it from the battlefield to your hand, copying Turnabout.
Resolve the copy of Turnabout, untapping all lands you control.
Activate all mana-producing lands you control by tapping them, adding at least {4}{U}{R}.
Cast Rootha by paying {1}{U}{R}.
Repeat from step 3.

Infinite ETB

Infinite LTB

Infinite magecraft triggers

Infinite mana lands you control can produce

Infinite storm count

Infinite untap of lands you control

Rootha, Mercurial Artist

Turnabout

Raff Capashen, Ship's Mage

Activate all mana-producing nonland permanents you control by tapping them, adding at least {3}{U}{R}.
Cast Dramatic Reversal by paying {1}{U}.
Activate Rootha by paying {2} and returning it to your hand, copying Dramatic Reversal.
Resolve the Dramatic Reversal copy, untapping all nonland permanents you control.
Activate all mana-producing nonland permanents you control by tapping them, adding at least {3}{U}{R}.
Cast Rootha by paying {1}{U}{R}.
Repeat from step 3.
If nonland permanents you control can tap to produce at least {4}{U}{R}, this combo nets infinite mana.

Infinite mana nonland permanents you control can produce

Infinite untap of nonland permanents you control

Dramatic Reversal

Cast Jeska's Will by paying {2}{R}.
Storm-Kiln Artist triggers, creating a Treasure token.
Activate a Treasure by tapping and sacrificing it, adding {1}.
Holding priority, activate Rootha by paying {2} and returning it from the battlefield to your hand, copying Jeska's Will.
Storm-Kiln Artist triggers, creating a Treasure token.
Resolve the Jeska's Will copy, adding at least {R}{R}{R}{R}.
Activate a Treasure by tapping and sacrificing it, adding {U}.
Cast Rootha by paying {1}{U}{R}.
Repeat from step 4.

Infinite red mana

Exile your library with the ability to play the exiled cards until end of turn

Jeska's Will

Storm-Kiln Artist

Cast Brass's Bounty by paying {6}{R}.
Holding priority, activate Rootha by paying {2} and returning it from the battlefield to your hand, copying Brass's Bounty.
Resolve the Brass's Bounty copy, creating at least six Treasure tokens.
Activate five Treasure tokens by tapping and sacrificing them, adding {3}{U}{R}.
Cast Rootha by paying {1}{U}{R}.
Repeat from step 2.

Infinite colored mana

Infinite Treasure tokens

Brass's Bounty

Cast Seething Song by paying {2}{R}.
Storm-Kiln Artist triggers, creating a Treasure token.
Activate a Treasure by tapping and sacrificing it, adding {1}.
Holding priority, activate Rootha by paying {2} and returning it from the battlefield to your hand, copying Seething Song.
Storm-Kiln Artist triggers, creating a Treasure token.
Resolve the Seething Song copy, adding {R}{R}{R}{R}{R}.
Activate a Treasure by tapping and sacrificing it, adding {U}.
Cast Rootha by paying {1}{U}{R}.
Repeat from step 4.

Seething Song

On the end step prior to your turn, cast Storvald either from your hand or from the command zone by paying {4}{G}{W}{U} and commander tax, if applicable.
When Storvald enters the battlefield, it triggers, causing Tree or Redemption's power and toughness to become 1 until end of turn.
Activate Tree of Redemption by tapping it, causing your life total to become 1.
At the beginning of your upkeep, Near-Death Experience triggers, causing you to win the game.

Win the game at the beginning of your next upkeep

Storvald, Frost Giant Jarl

Tree of Redemption

Near-Death Experience

Activate any number of basic lands by tapping them, adding at least {3}{U}{R}.
Cast Early Harvest by paying {1}{G}{G}.
Holding priority, activate Rootha by paying {2} and returning it from the battlefield to your hand, copying Early Harvest
Resolve the Early Harvest copy, untapping all basic lands you control.
Activate any number of basic lands by tapping them, adding at least {3}{U}{R}.
Cast Rootha by paying {1}{U}{R}.
Repeat from step 3.

Infinite mana basic lands you control can produce

Infinite untap of basic lands you control

Early Harvest

Activate any number of lands by tapping them, adding at least {3}{U}{R}.
Cast Rude Awakening by paying {4}{G}.
Holding priority, activate Rootha by paying {2} and returning it from the battlefield to your hand, copying Rude Awakening.
Resolve the Rude Awakening copy, untapping all lands you control.
Activate any number of lands by tapping them, adding at least {3}{U}{R}.
Cast Rootha by paying {1}{U}{R}.
Repeat from step 3.

Combos with "Raff Capashen, Ship's Mage"