An opponent owns at least two cards in exile with hit counters on them.
Each opponent controls at least three nontoken creatures, minus one for each card they own in exile with a hit counter on it.
Steps
Declare
Etrata as an attacker, attacking an opponent that owns at least two cards in exile with hit counters on them.
Etrata's myriad ability triggers, creating four copies of it attacking each other opponent.
Deal combat damage with each
Etrata, triggering their abilities.
Resolve the first
Etrata ability, causing the opponent dealt damage by it to exile a creature they control with a hit counter on it, and lose the game if they have at least three cards in exile with hit counters on them.
Repeat step 4 for each remaining trigger.
Results
Each opponent loses the game.
Metadata
Bracket tag
ExhibitionBracket 1+
For any deck
1
2
3
4
5
1 · Exhibition5 · cEDH
Bracket tags are estimated from the cards and results of each combo, as a guideline rather than a strict classification.