Chronomantic Escape + Sphinx of the Second Sun + Vesuvan Shapeshifter

Chronomantic Escape

Sphinx of the Second Sun

Vesuvan Shapeshifter

How it works

1. Cast Chronomantic Escape by paying 4, causing creatures to be unable to attack you until your next turn, and putting Chronomantic Escape into exile with three time counters on it.
2. At the beginning of your postcombat main phase, both copies of Sphinx of the Second Sun trigger, causing you to get two additional beginning phases after this phase.
3. Move to your first additional beginning phase.
4. At the beginning of your upkeep, Chronomantic Escape triggers, removing a time counter from itself.
5. Repeat from step 3 one additional time.
6. At the beginning of your next upkeep, Chronomantic Escape triggers, removing a time counter from itself and causing you to cast it without paying its mana cost.
7. Resolve Chronomantic Escape, causing creatures to be unable to attack you until your next turn, and putting Chronomantic Escape into exile with three time counters on it.
8. Repeat from step 2.

By letting Sphinx of the Second Sun repeatedly grant you extra beginning phases packed with untap, upkeep, and draw steps, you drastically accelerate the countdown on Chronomantic Escape. Vesuvan Shapeshifter is the linchpin here, copying the Sphinx to double down on those extra upkeep triggers so you can rapidly strip away all three time counters in a single turn cycle. Once Chronomantic Escape casts itself for free, it immediately exiles itself again with a fresh set of time counters, locking down the combat step so that creatures can never attack you again.