Activate Phyrexian Colossus by paying life.
Repeat step 1 as desired.
Activate Rowan by tapping it, reducing the cost of all black and/or red spells you cast this turn.
Cast Exsanguinate, choosing for X to equal the amount of life you've lost this turn, but paying a total of {B}{B} due to Rowan.
Resolve Exsanguinate, causing each opponent to lose X life, and you to gain life equal to the life lost this way.

Near-infinite lifegain

Near-infinite lifeloss

Rowan, Scion of War

Exsanguinate

Phyrexian Colossus

Activate Phyrexian Colossus by tapping it, dealing 8 damage to any target and causing you to gain eight life.
Activate Phyrexian Colossus by paying eight life, untapping it.
Repeat.

Infinite damage

Infinite lifegain triggers

Burning Anger

Basilisk Collar

Activate Phyrexian Colossus by tapping it, dealing eleven damage to any target and causing you to gain eleven life.
Activate Phyrexian Colossus by paying eight life, untapping it.
Repeat.

Infinite lifegain

Loxodon Warhammer

Activate Phyrexian Colossus by tapping it, dealing 9 damage to any target and causing you to gain nine life.
Activate Phyrexian Colossus by paying eight life, untapping it.
Repeat.

Shadowspear

Activate Phyrexian Colossus by paying 8 life.
Repeat step 1 until Greven has power 21 or greater due to its first ability.
Deal combat damage to an opponent using Greven. The opponent loses the game due to being dealt 21 or more combat damage from your commander.

Target opponent loses the game

Greven, Predator Captain

Activate Necrotic Ooze using Auriok Bladewarden's ability by tapping it, giving itself +X/+X until end of turn, where X is Necrotic Ooze's power.
Activate Necrotic Ooze using Phyrexian Colossus' ability by paying eight life, untapping it.
Repeat two additional times.
Activate Necrotic Ooze using Tree of Redemption's ability by tapping it, causing you to swap your life total with Necrotic Ooze's toughness.
Activate Necrotic Ooze using Phyrexian Colossus' ability by paying eight life, untapping it.
Activate Necrotic Ooze using Auriok Bladewarden's ability by tapping it, giving itself +X/+X until end of turn, where X is Necrotic Ooze's power.
Activate Necrotic Ooze using Phyrexian Colossus' ability by paying eight life, untapping it.
Repeat from step 4.

Infinitely large creatures you control until end of turn

Necrotic Ooze

Tree of Redemption

Auriok Bladewarden

Lifelink

Activate Phyrexian Colossus by paying life.
Repeat step 1 as desired.
Activate Rowan by tapping it, reducing the cost of all black and/or red spells you cast this turn.
Cast a copy of Exsanguinate, choosing for X to equal the amount of life you've lost this turn, but paying a total of {B}{B} due to Rowan.
Resolve Exsanguinate, causing each opponent to lose X life, and you to gain life equal to the life lost this way.

Combos with "Phyrexian Colossus"