Glimmervoid Basin

The controller of a face-up plane card is the player designated as the "planar controller." Normally, the planar controller is whoever the active player is. However, if the current planar controller would leave the game, instead the next player in turn order that wouldn't leave the game becomes the planar controller, then the old planar controller leaves the game. The new planar controller retains that designation until they leave the game or a different player becomes the active player, whichever comes first.

A plane card is treated as if its text box included "When you roll {PW}, put this card on the bottom of its owner's planar deck face down, then move the top card of your planar deck off that planar deck and turn it face up." This is called the "planeswalking ability."

If the spell that's copied has an X whose value was determined as it was cast (like Earthquake does), the copy has the same value of X.

As a token is created by the chaos ability, it checks the printed values of the creature it's copying, as well as any copy effects that have been applied to it. It won't copy counters on the creature, nor will it copy other effects that have changed the creature's power, toughness, types, color, and so on.

The controller of a copy can't choose to pay any additional costs for the copy. However, effects based on any additional costs that were paid for the original spell are copied as though those same costs were paid for the copy too.

If a spell targets multiple things, it won't cause Glimmervoid Basin's first ability to trigger, even if all but one of those targets has become illegal.

The copies that Glimmervoid Basin's first ability creates are created on the stack, so they're not "cast." Abilities that trigger when a player casts a spell (like Glimmervoid Basin's first ability itself) won't trigger.

The controller of the spell that caused Glimmervoid Basin's first ability to trigger also controls all the copies. That player chooses the order the copies are put onto the stack. The original spell will be on the stack beneath those copies and resolves last.

If a spell targets the same player or object multiple times, it won't cause Glimmervoid Basin's first ability to trigger.

If the spell that's copied is modal (that is, it says "Choose one —" or the like), the copy will have the same mode. Its controller can't choose a different one.

If an ability of a plane refers to "you," it's referring to whoever the plane's controller is at the time, not to the player that started the game with that plane card in their deck. Many abilities of plane cards affect all players, while many others affect only the planar controller, so read each ability carefully.