When an opponent moves a unit into an empty battlefield and I use Zenith Blade/Ride the Wind to move my unit into that same battlefield during my priority, am I the attacker or defender?

Ruling: You are the defender. The opponent applies contested status to the battlefield when they move their unit there, which happens before you can respond with reactions.

Sequence:

• Opponent moves unit into empty battlefield
• Contested status is applied to the battlefield
• You respond with Zenith Blade/Ride the Wind to move your unit there
• You are the defender since the battlefield was already contested before your unit arrived

Nuances:

• This interaction nullifies legends like Ahri/Yi that require you to be the attacker