Coercive Recruiter + Splinter Twin

Coercive Recruiter
Splinter Twin

Requires
All permanents on the battlefield. Splinter Twin attached to Coercive Recruiter. Coercive Recruiter does not have summoning sickness.
Steps
  1. Activate Coercive Recruiter by tapping it, creating a token copy of itself with haste
  2. The token Coercive Recruiter enters the battlefield, untapping the nontoken Coercive Recruiter
  3. Repeat
Results
Infinite creature tokens with haste. Infinite ETB.