Requires

Mishra, Eminent One must be on the battlefield. Urza, Lord High Artificer must be on the battlefield. Worldwalker Helm must be on the battlefield. Hammer of Purphoros must be on the battlefield. Mana needed:

Steps

1. At the beginning of your combat phase, Mishra triggers, creating a token copy of Worldwalker Helm that is a 4/4 Construct artifact creature with haste named Mishra's Warform, and a Map token.
2. Activate Urza's first ability by tapping a Map, adding .
3. Activate Mishra's Warform by paying and tapping it, creating a token copy of it and a Map token for each Mishra's Warform and/or Worldwalker Helm you control.
4. Activate Urza's first ability twice by tapping two Maps, adding .
5. Repeat from step 3.

Results