109.5

The words "you" and "your" on an object refer to the object's controller,

Absorb.

Abyssal Persecutor.

its would-be controller (if a player is attempting to play, cast, or activate it),

Gravecrawler.

or its owner (if it has no controller).

Serum Powder

For a static ability, this is the current controller of the object it's on.

Glorious Anthem.

For an activated ability, this is the player who activated the ability.

Xantcha, Sleeper Agent.

For a triggered ability, this is the controller of the object when the ability triggered, unless it's a delayed triggered ability. To determine the controller of a delayed triggered ability, see rules 603.7d-f.