Cast Gideon's Sacrifice by paying {W}, targeting Anti-Venom
Whenever damage would be dealt to you, Gideon's Sacrifice causes that damage to be redirected to Anti-Venom.
Anti-Venom will then prevent the damage and put that many +1/+1 counters on it instead.

Prevent all damage that would be dealt to you

Lock

Anti-Venom, Horrifying Healer

Gideon's Sacrifice

Cast Gideon's Sacrifice by paying {W}, targeting a creature you control.
Whenever damage would be dealt to you, Gideon's Sacrifice causes that damage to be redirected to the creature it's attached to.
Vigor will then prevent the damage and put that many +1/+1 counters on that creature instead.

Vigor

Cast Gideon's Sacrifice by paying {W}, targeting Barbed Servitor
Deal damage to Barbed Servitor
Barbed Servitor and Fiendlash trigger.
Resolve the Barbed Servitor trigger, causing an opponent to lose life equal to the damage dealt to Barbed Servitor.
Resolve the Fiendlash trigger, targeting you, but dealing damage to Barbed Servitor instead due to Gideon's Sacrifice.
Repeat from step 3.

Infinite lifeloss

Fiendlash

Barbed Servitor

Cast Gideon's Sacrifice by paying {W}, causing all damage that would be dealt this turn to you or to permanents you control to be dealt to Crystalline Crawler instead.
Activate Pestilence Demon by paying {B}, dealing 1 damage to each creature and each player.
Gideon's Sacrifice redirects damage to Crawler, which results in at least four +1/+1 counters being placed on it instead due to Vigor.
Activate Crystalline Crawler's first activated ability at least once by removing at least one +1/+1 counter from it, adding at least {B}.
Repeat from step 2.

Infinite colored mana

Infinite damage

Infinite +1/+1 counters on a creature

Crystalline Crawler

Pestilence Demon

Cast Gideon's Sacrifice by paying {W}, causing all damage that would be dealt this turn to you or to permanents you control to be dealt to Crystalline Crawler instead.
Activate Thrashing Wumpus by paying {B}, dealing 1 damage to each creature and each player.
Gideon's Sacrifice redirects damage to Crawler, which results in at least four +1/+1 counters being placed on it instead due to Vigor.
Activate Crystalline Crawler's first activated ability at least once by removing at least one +1/+1 counter from it, adding at least {B}.
Repeat from step 2.

Thrashing Wumpus

Cast Gideon's Sacrifice by paying {W}, causing all damage that would be dealt this turn to you or to permanents you control to be dealt to Crystalline Crawler instead.
Activate Pestilence by paying {B}, dealing 1 damage to each creature and each player.
Gideon's Sacrifice redirects damage to Crawler, which results in at least three +1/+1 counters being placed on it instead due to Vigor.
Activate Crystalline Crawler's first activated ability at least once by removing at least one +1/+1 counter from it, adding at least {B}.
Repeat from step 2.

Near-infinite damage

Near-infinite +1/+1 counters on most creatures you control

Pestilence

Cast Gideon's Sacrifice by paying {W}, causing all damage that would be dealt this turn to you or to permanents you control to be dealt to Crystalline Crawler instead.
Activate Scourge of Kher Ridges's first ability by paying {1}{R}, dealing 2 damage to each creature without flying.
Gideon's Sacrifice redirects damage to Crawler, which results in at least three +1/+1 counters being placed on it instead due to Vigor.
Activate Crystalline Crawler's first activated ability at least twice by removing at least two +1/+1 counters from it, adding at least {1}{R}.
Repeat from step 2.

Infinite damage to creatures

Scourge of Kher Ridges

Cast Gideon's Sacrifice by paying {W}, causing all damage that would be dealt this turn to you or to permanents you control to be dealt to Crystalline Crawler instead.
Activate Ashen Firebeast by paying {1}{R}, dealing 1 damage to each creature without flying.
Gideon's Sacrifice redirects damage to Crawler, which results in at least three +1/+1 counters being placed on it instead due to Vigor.
Activate Crystalline Crawler's first activated ability at least twice by removing at least two +1/+1 counters from it, adding at least {1}{R}.
Repeat from step 2.

Infinite damage to some creatures

Ashen Firebeast

Cast Gideon's Sacrifice by paying {W}, causing all damage that would be dealt this turn to you or to permanents you control to be dealt to Crystalline Crawler instead.
Activate Pyrohemia by paying {R}, dealing 1 damage to each creature and each player.
Gideon's Sacrifice redirects damage to Crawler, which results in at least three +1/+1 counters being placed on it instead due to Vigor.
Activate Crystalline Crawler's first activated ability at least once by removing a +1/+1 counter from it, adding at least {R}.
Repeat from step 2.

Pyrohemia

Cast Gideon's Sacrifice by paying {W}, causing all damage that would be dealt this turn to you or to permanents you control to be dealt to Crystalline Crawler instead.
Cast Warmonger by paying {3}{R}.
Activate Warmonger by paying {2}, dealing 1 damage to each creature without flying and each player.
Gideon's Sacrifice redirects damage to Crawler, which results in at least four +1/+1 counters being placed on it instead due to Vigor.
Activate Crystalline Crawler's first activated ability at least twice by removing at least two +1/+1 counters from it, adding at least {2}.
Repeat from step 3.

Combos with "Gideon's Sacrifice"