Requires

Doomsday must be in hand. Grenzo, Dungeon Warden must be on the battlefield. Metallic Mimic must be in the graveyard, or in the library. Murderous Redcap must be in the graveyard, or in the library. Kiki-Jiki, Mirror Breaker must be in the graveyard, or in the library. Priest of Gix must be in the graveyard, or in the library. Skirk Prospector must be in the graveyard, or in the library. Your life total is at least 2. Mana needed:

Steps

1. Cast Doomsday by paying , searching your library and graveyard for Metallic Mimic, Murderous Redcap, Skirk Prospector, Kiki-Jiki, and Priest of Gix, exiling all other cards from your graveyard and library, and then placing the remaining cards on top of your library in the order previously listed and losing half your life, rounded up.
2. Activate Grenzo by paying , putting Priest of Gix into your graveyard and then onto the battlefield, adding .
3. Activate Grenzo by paying , putting Kiki-Jiki into your graveyard and then onto the battlefield.
4. Activate Kiki-Jiki by tapping, creating a token copy of Priest of Gix.
5. Token copy of Priest of Gix entering the battlefield, adding .
6. Activate Grenzo by paying , putting Skirk Prospector into your graveyard and then onto the battlefield.
7. Activate Grenzo by paying , putting Murderous Redcap into your graveyard and then onto the battlefield, dealing damage equal to its power to any target.
8. Activate Skirk Prospector by sacrificing Kiki-Jiki and Murderous Redcap, adding .
9. Murderous Redcap persist ability triggers, holding priority, activate Grenzo by paying , putting Metallic Mimic into your graveyard and then onto the battlefield, naming "Goblin".
10. Resolve the Murderous Redcap persist ability, returning it to the battlefield, dealing damage equal to its power to any target.
11. Activate Skirk Prospector by sacrificing Murderous Redcap, adding .
12. Murderous Redcap persist ability triggers, returning it to the battlefield, dealing damage equal to its power to any target.
13. Repeat from step 11.

Results