March of the Machine Commander

Orochi Colony

Whenever a creature you control deals combat damage to a player, you may search your library for a basic land card, put it onto the battlefield tapped, then shuffle.
Whenever chaos ensues, target creature can't be blocked this turn.

Planechase Anthology Planes

Whenever a creature you control deals combat damage to a player, you may search your library for a basic land card, put it onto the battlefield tapped, then shuffle your library.
Whenever you roll {Chaos}, target creature can't be blocked this turn.

Planechase 2012 Planes

Whenever a creature you control deals combat damage to a player, you may search your library for a basic land card, put it onto the battlefield tapped, then shuffle your library.
Whenever you roll chaos, target creature is unblockable this turn.