Activate Kuro by paying 1 life, targeting any creature not used for this combo.
Holding priority, repeat the previous step until you have 1 life remaining.
Resolve all Kuro abilities.
Cast Repay in Kind by paying {5}{B}{B}, causing all life totals to become 1.
Cast Temporal Extortion by paying {B}{B}{B}{B}.
If an opponent pays 1 life to counter it, that opponent's life total becomes 0, they lose the game, and you skip the next step.
Otherwise, resolve Temporal Extortion, gaining an extra turn.
Activate Canal Dredger by tapping it, putting Temporal Extortion from your graveyard on the bottom of your library.
Declare Varragoth as an attacker.
Activate Varragoth's Boast ability by paying {1}{B}, searching your library for Temporal Extortion and putting on top of your library.
Go to your next turn.
Draw Temporal Extortion in your draw step.
Repeat from step 7.

On each of your turns, you take an extra turn unless an opponent chooses to lose the game

Lock

Varragoth, Bloodsky Sire

Kuro, Pitlord

Temporal Extortion

Repay in Kind

Canal Dredger

Cast Temporal Extortion by paying {B}{B}{B}{B}.
Temporal Extortion and Mirari trigger.
Resolve the Mirari trigger, paying {3} and copying Temporal Extortion.
Resolve the Temporal Extortion copy, causing you to take an extra turn after this one.
Resolve the Temporal Extortion trigger, allowing any player to pay half their life to counter the spell.
If no one does, resolve Temporal Extortion, causing you to take an extra turn after this one.
Activate Canal Dredger by tapping it, putting Temporal Extortion on the bottom of your library.
Declare Varragoth as an attacker.
Pay {1}{B} to activate Varragoth, searching your library for Temporal Extortion and putting it on top.
Repeat each turn.

Infinite turns

Mirari

Activate Unspeakable Symbol as many times as possible by paying all but 1 life, putting +1/+1 counters on creatures you control Cast Repay in Kind by paying {5}{B}{B}, causing all life totals to become 1.
Cast Temporal Extortion by paying {B}{B}{B}{B}.
If an opponent pays 1 life to counter it, that opponent's life total becomes 0, they lose the game, and you skip the next step.
Otherwise, resolve Temporal Extortion, gaining an extra turn.
Activate Canal Dredger by tapping it, putting Temporal Extortion from your graveyard on the bottom of your library.
Declare Varragoth as an attacker.
Activate Varragoth's Boast ability by paying {1}{B}, searching your library for Temporal Extortion and putting on top of your library.
Go to your next turn.
Draw Temporal Extortion in your draw step.
Repeat from step 7.

Combos with "Canal Dredger"