Necromancy + Worldgorger Dragon

Necromancy
Worldgorger Dragon

Requires
Necromancy must be in hand. Worldgorger Dragon must be in the graveyard. Mana needed: 2b
Steps
  1. Cast Necromancy by paying 2b.
  2. Animate Dead enters the battlefield, returning Worldgorger Dragon from your graveyard to the battlefield attached with Necromancy.
  3. Worldgorger Dragon enters the battlefield, exiling all other permanents you control.
  4. Necromancy triggers, sacrificing Worldgorger Dragon.
  5. Worldgorger Dragon leaves the battlefield, returning all permanents exiled by it to the battlefield.
  6. Necromancy enters the battlefield, returning Worldgorger Dragon from your graveyard to the battlefield attached with Necromancy.
  7. Holding priority, activate all lands you control by tapping those, adding manas of any colors those lands can produce.
  8. Repeat.
Results
Infinite colored mana. Infinite colorless mana. Infinite ETB. Infinite LTB. Infinite sacrifice triggers.