Activate Mairsil using Ventifact Bottle's ability by paying {4} and tapping it, putting three +1/+1 counters on Mairsil.
Activate Mairsil using Horseshoe Crab's ability by paying {U}, untapping itself.
Activate Mairsil using Magistrate's Scepter's last ability by tapping it, gaining an extra turn after this one.
Move to your next turn.
Repeat.

Infinite turns

Lock

Mairsil, the Pretender

Ventifact Bottle

Magistrate's Scepter

Horseshoe Crab

Activate Mairsil using Ventifact Bottle's ability by paying {4} and tapping it, putting three +1/+1 counters on Mairsil.
Activate Mairsil using Staff of Domination's first ability by paying {1}, untapping itself.
Activate Mairsil using Magistrate's Scepter's last ability by tapping it, gaining an extra turn after this one.
Move to your next turn.
Repeat.

Staff of Domination

Activate The Enigma Jewel's first ability by tapping it, if able, adding {C}{C} that can only be spent to activate abilities.
Activate The Enigma Jewel's second ability by paying {8}{U}, exiling it, exiling Magistrate's Scepter and Ventifact Bottle either from the battlefield or from your graveyard, and exiling two other nonland cards with activated abilities either from the battlefield or from your graveyard, returning The Enigma Jewel to the battlefield transformed.
Activate Locus of Enlightenment using Ventifact Bottle's ability by paying {3} and tapping it.
Locus of Enlightment triggers, copying its ability.
Resolve both Locus of Enlightenment abilities, putting four charge counters on it.
During your next turn, activate Locus of Enlightment using Magistrate Scepter's second ability by tapping it and removing three charge counters from it.
Locus of Enlightment triggers, copying its ability.
Resolve both Locus of Enlightenment abilities, causing you to take two extra turns after this one.
Move to your next turn.
Repeat from step 3.

Combos with "Ventifact Bottle"