Karn Turbine

Whenever Karn blocks or becomes blocked, it gets -4/+4 until end of turn. : Target noncreature artifact becomes an artifact creature with power and toughness each equal to its mana value until end of turn.

Creatures don't untap during their controllers' untap steps. Whenever a creature enters, untap all creatures.

: Create a 1/1 colorless Myr artifact creature token. , Tap five untapped Myr you control: Search your library for a Myr creature card, put it onto the battlefield, then shuffle.