the front side of Gyre Engineer
the back of a classic MtG card
the front side of Umbral Mantle
the back of a classic MtG card
the front side of Heartstone
the back of a classic MtG card

Color Identity: G, U

Initial Card State

  1.  All permanents on the battlefield.

Notable Prerequisites

  1. Umbral Mantle attached to Gyre Engineer.
  2. Gyre Engineer does not have summoning sickness.

Steps

  1. Activate Gyre Engineer by tapping it, adding one green manaone blue mana.
  2. Activate Gyre Engineer by paying two generic mana and untapping it, giving itself +2/+2 until end of turn.
  3. Repeat.

Results

  1. Infinitely large creature until end of turn.
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