Graaz, Unstoppable Juggernaut

Juggernauts you control attack each combat if able.
Juggernauts you control can't be blocked by Walls.
Other creatures you control have base power and toughness 5/3 and are Juggernauts in addition to their other creature types.

Phyrexia: All Will Be One

Phyrexia: All Will Be One Promos

If Graaz loses its abilities for some reason, then Juggernauts you control will not have to attack each combat and will be able to be blocked by Walls. However, due to how continuous effects are applied in layers, other creatures you control will continue to be 5/3 Juggernauts in addition to their other types. Unstoppable, indeed!