Mikaeus, the Unhallowed + Triskelion

Mikaeus, the Unhallowed
Triskelion

Requires
All permanents on the battlefield. Triskelion has at least two +1/+1 counters on it.
Steps
  1. If Triskelion has at least three +1/+1 counters on it, activate Triskelion by removing a +1/+1 counter from it, dealing 1 damage to any target
  2. Repeat step 1 until there are two +1/+1 counters remaining on Triskelion
  3. Activate Triskelion by removing a +1/+1 counter from Triskelion, dealing 1 damage to itself
  4. Repeat step 3 an additional time
  5. Triskelion dies
  6. Triskelion's undying ability triggers, returning it to the battlefield with an additional +1/+1 counter on it
  7. Repeat
Results
Infinite damage. Infinite death triggers. Infinite ETB. Infinite LTB.