Cause any creature to enter the battlefield under your control, triggering Jaws of Defeat.
Holding priority, cast Overkill by paying {2}{B}, giving the creature that entered -0/-9999 until end of turn.
The creature dies as a state-based action due to having less than 0 toughness.
Resolve the Jaws of Defeat trigger, causing target opponent to lose life equal to the difference between the creature's power and toughness, using its last known information.

Target opponent loses the game

Near-infinite lifeloss for target opponent

Overkill

Jaws of Defeat

Cast Tree of Perdition by paying {3}{B}.
When Tree of Perdition enters the battlefield, Jaws of Defeat triggers, targeting an opponent.
If the opponent has 13 or more life, hold priority and then activate Tree of Perdition by tapping it, swapping its toughness with an opponent's life total.
Resolve the Jaws of Defeat trigger, causing the opponent targeted in step 3 to lose life equal to Tree of Perdition's toughness.
The opponent loses the game as a state-based action due to having 0 or less life.

Infinite lifeloss for target opponent

Tree of Perdition

Thousand-Year Elixir

Cast Viscid Lemures by paying {4}{B}
When Viscid Lemures enters the battlefield, Jaws of Defeat triggers.
Holding priority, activate Viscid Lemures by paying {0}, giving it -1/-0 and swampwalk until end of turn.
Repeat step 3 an arbitrarily large number of times.
Resolve the Jaws of Defeat trigger, causing an opponent to lose life equal to the difference between Viscid Lemures' power and toughness.

Viscid Lemures

Cast Hyalopterous Lemure by paying {4}{B}.
When Hyalopterous Lemure enters the battlefield, Jaws of Defeat triggers.
Holding priority, activate Hyalopterous Lemure by paying {0}, giving it -1/-0 until end of turn.
Repeat step 3 an arbitrarily large number of times.
Resolve the Jaws of Defeat trigger, causing target opponent to lose life equal to the difference between Hyalopterous Lemure's power and toughness.

Hyalopterous Lemure

Cast Daru Spiritualist by paying {1}{W}.
When Daru Spiritualist enters the battlefield, Jaws of Defeat triggers.
Holding priority, activate Shaman en-Kor by paying {0}, targeting Daru Spiritualist.
Daru Spiritualist triggers, giving it +0/+2 until end of turn.
Resolve the Shaman en-Kor ability.
Repeat from step 3 an arbitrarily large number of times.
Resolve the Jaws of Defeat trigger, causing an opponent to lose an arbitrarily large amount of life.

Combos with "Jaws of Defeat"