Warping Wurm

Phasing is a static ability that modifies the rules of the untap step. During each player’s untap step, before the active player untaps permanents, all phased-in permanents with phasing that player controls “phase out.” Simultaneously, all phased-out permanents that had phased out under that player’s control “phase in.”

If a permanent phases out, its status changes to “phased out.” Except for rules and effects that specifically mention phased-out permanents, a phased-out permanent is treated as though it does not exist. It can’t affect or be affected by anything else in the game. A permanent that phases out is removed from combat. (See rule 506.4.)

If a permanent phases in, its status changes to “phased in.” The game once again treats it as though it exists.

The phasing event doesn’t actually cause a permanent to change zones or control, even though it’s treated as though it’s not on the battlefield and not under its controller’s control while it’s phased out. Zone-change triggers don’t trigger when a permanent phases in or out. Tokens continue to exist on the battlefield while phased out. Counters and stickers remain on a permanent while it’s phased out. Effects that check a phased-in permanent’s history won’t treat the phasing event as having caused the permanent to leave or enter the battlefield or its controller’s control.

If a continuous effect generated by the resolution of a spell or ability modifies the characteristics or changes the controller of any objects, a phased-out permanent won’t be included in the set of affected objects. This includes continuous effects that reference the permanent specifically, unless they also specifically refer to the permanent as phased out.

Continuous effects that affect a phased-out permanent may expire while that permanent is phased out. If so, they will no longer affect that permanent once it’s phased in. In particular, effects with “for as long as” durations that track that permanent (see rule 611.2b) end when that permanent phases out because they can no longer see it.

When a permanent phases out, any Auras, Equipment, or Fortifications attached to that permanent phase out at the same time. This alternate way of phasing out is known as phasing out “indirectly.” An Aura, Equipment, or Fortification that phased out indirectly won’t phase in by itself, but instead phases in along with the permanent it’s attached to.

If an object would simultaneously phase out directly and indirectly, it just phases out indirectly.

An Aura, Equipment, or Fortification that phased out directly will phase in attached to the object or player it was attached to when it phased out, if that object is still in the same zone or that player is still in the game. If not, that Aura, Equipment, or Fortification phases in unattached. State-based actions apply as appropriate. (See rules 704.5m and 704.5n.)

Abilities that trigger when a permanent becomes attached or unattached from an object or player don’t trigger when that permanent phases in or out.

Phased-out permanents owned by a player who leaves the game also leave the game. This doesn’t cause zone-change abilities to trigger. See rule 800.4.

If an effect causes a player to skip their untap step, the phasing event simply doesn’t occur that turn.

In a multiplayer game, game rules may cause a phased-out permanent to leave the game or to be exiled once a player leaves the game. (See rules 800.4a and 800.4c.) If a phased-out permanent phased out under the control of a player who has left the game, that permanent phases in during the next untap step after that player’s next turn would have begun.

Multiple instances of phasing on the same permanent are redundant.