Activate Coretapper's first ability by tapping it, putting a charge counter on Magistrate's Scepter.
Activate Contagion Clasp by paying {4} and tapping it, proliferating twice, putting two additional charge counters on Magistrate's Scepter.
Activate Magistrate's Scepter's second ability by tapping it and removing three charge counters from it, taking an extra turn after this one.
Repeat each turn.

Infinite turns

Tekuthal, Inquiry Dominus

Magistrate's Scepter

Coretapper

Contagion Clasp

Activate Contagion Clasp by paying {4} and tapping it, putting an eon counter on Magosi.
Activate Nesting Grounds's last ability by paying {1} and tapping it, moving an eon counter from Magosi to Nesting Grounds.
Activate Magosi's last ability by tapping it, removing an eon counter from it and returning it to your hand, taking an extra turn after this one.
Play Magosi from your hand.
Move to your next turn.
Activate Contagion Clasp by paying {4} and tapping it, putting an eon counter on Nesting Grounds.
Activate Nesting Grounds's last ability by paying {1} and tapping it, moving an eon counter from Nesting Grounds to Magosi.
Repeat from step 3.

Magosi, the Waterveil

Nesting Grounds

Activate Contagion Clasp by paying {4} and tapping it.
Kurkesh triggers, choose not to pay for the trigger.
Resolve the Contagion Clasp ability, putting a charge counter on Magistrate's Scepter.
Activate Magistrate's Scepter's second ability by tapping it and removing three charge counters from it.
Kurkesh triggers, causing you to pay {R} to copy Magistrate's Scepter's ability.
Resolve both Magistrate Scepter abilities, causing you to take two extra turns after this one.
Move to your next turn.
Activate Magistrate's Scepter's first ability by paying {4} and tapping it.
Kurkesh triggers, causing you to pay {R} to copy Magistrate's Scepter's ability.
Resolve both Magistrate Scepter abilities, putting two charge counters on it.
Move to your next turn.
Repeat.

Kurkesh, Onakke Ancient

Activate Contagion Engine by paying {4} and tapping it, putting two loyalty counters on each planeswalker you control.
Activate Contagion Clasp by paying {4} and tapping it, putting a loyalty counter on each planeswalker you control.
Activate Ajani's second loyalty ability by removing two loyalty counters from it, putting a loyalty counter on each other planeswalker you control.
Activate Teferi's third loyalty ability by removing ten loyalty counters from it, causing you to take two extra turns after this one.
Activate Aminatou's second loyalty ability by removing a loyalty counter from it, blinking Teferi.
Activate Teferi's first loyalty ability by putting a loyalty counter on it, causing you to loot.
Move to your first extra turn.
Activate Teferi's first loyalty ability by putting a loyalty counter on it, causing you to loot.
Repeat steps 1 and 2 one additional time.
Move to your second extra turn.
Repeat.

Aminatou, the Fateshifter

Teferi, Master of Time

Contagion Engine

During your precombat main phase, activate Contagion Clasp by paying {4} and tapping it, putting an eon counter on Magosi.
Activate Magosi's third ability by tapping it, removing an eon counter from it and returning it from the battlefield to your hand.
When Magosi leaves the battlefield, The Ozolith's first ability triggers, putting an eon counter on The Ozolith.
Resolve the Magosi ability, causing you to take an extra turn after this one.
Play Magosi.
At the beginning of your combat phase, The Ozolith triggers, putting an eon counter on Magosi.
Repeat each turn.

The Ozolith

Nature's Revolt

Living Plane

Activate Urabrask by paying {R}, exiling it and returning it to the battlefield as The Great Work.
As The Great Work enters the battlefield, a lore counter is placed on it.
The Great Work triggers, dealing three damage to an opponent and each creature they control.
Activate Contagion Clasp by paying {4} and tapping it, putting two lore counters on The Great Work.
The Great Work's second and third abilities trigger.
Resolve the first Great Work trigger, creating three Treasure tokens.
Resolve the second Great Work trigger, allowing you to cast instants and sorceries from graveyards this turn, and then exiling The Great Work and returning it to the battlefield as Urabrask.
Activate Clock of Omens by tapping two Treasures, untapping Contagion Clasp.
Activate Krark-Clan Ironworks twice by sacrificing the two tapped Treasures, adding {C}{C}{C}{C}.
Activate the final Treasure by tapping and sacrificing it, adding {R}.
Repeat.

Combos with "Contagion Clasp"