When Green Yasuo uses his attack ability to deal damage, then is moved to another battlefield with Ride the Wind and then moved again with Flash, does the Mountain Drake heal the initial ability damage before Yasuo can attack again?

Ruling: Yes, the Mountain Drake heals before Yasuo can attack again. A showdown must fully resolve (including cleanup and healing) before a second showdown can begin, even if units leave the battlefield during the first showdown.

Sequence:

• Yasuo moves into Battlefield A and deals 6 ability damage to Mountain Drake, starting a showdown
• Player A casts Ride the Wind to move Yasuo to Battlefield B
• Player B passes focus
• Player A passes focus
• The first showdown ends and cleanup occurs (all units heal)
• If Battlefield B is contested, a new showdown begins there

Nuances:

• Showdowns do not automatically end just because there is only 1 or 0 players in the battlefield; the showdown only ends when both players pass focus
• When a second combat is created while a showdown is ongoing, it becomes "staged" and the turn player must resolve the already started combat first before addressing staged combats