Do 'When I attack' or 'When I defend' triggered abilities still resolve if the unit is moved back to base before the ability resolves?

Ruling: Attack/Defend triggers always resolve once placed on the chain (unless countered), but whether they have effect depends on if the ability uses location-based targeting.

Sequence:

• Unit moves to battlefield and gains Attacker/Defender designation
• The 'When I attack/defend' ability triggers and is placed on the chain
• Opponent can respond with spells (like Fight or Flight) while ability is on the chain
• If unit is moved back to base, a Cleanup occurs and the unit loses its Attacker/Defender designation
• The triggered ability still resolves
• Effect depends on whether ability has location-based requirements

Nuances:

• Abilities without location requirements (like Draven, Vanquisher's '+2 Might this turn') resolve with full effect even if the unit is at base, because buffs apply to the unit as a game object regardless of location
• Abilities with location-based targeting (like Azir, Sovereign's 'move units to this battlefield') resolve without effect if the unit is no longer at a battlefield, because the location reference is no longer valid
• Units lose Attacker/Defender designation during Cleanup when they are at locations other than the battlefield where combat is occurring
• Attack/Defend triggers can only be fulfilled once per combat, even if a unit gains and loses the designation multiple times