When Tideturner's ability is put on the chain, does it store the destination location at that time, or does it determine the destination on resolution?

Ruling: Tideturner's ability does not choose or store a location when activated. It targets a unit at a different location, and on resolution, Tideturner moves to whatever location that unit is currently at (as long as it's different from Tideturner's location).

Sequence:

• Tideturner hidden on battlefield A is played and targets a unit at battlefield B
• Flash is chained targeting Tideturner (Flash always moves to base, no choice)
• Flash resolves: Tideturner moves to base
• Tideturner's ability resolves: The unit moves from B to base (where Tideturner currently is), then Tideturner moves from base to B (where the unit was)

Nuances:

• The destination is determined on resolution based on current game state, not locked in when the ability is activated
• Even though Flash and Tideturner have fixed/restricted destinations, this doesn't mean the destination is "stored" when put on the chain