If a unit attacks a battlefield and then the opponent plays Flash, will Thwonk still stun the attacking unit?

Ruling: The timing of Flash relative to Thwonk determines the outcome. If Thwonk resolves first and stuns the attacking unit, then Flash is played afterward, the unit remains stunned for the turn. If Flash resolves before Thwonk, the target is no longer legal and Thwonk will fail to stun.

Sequence:

• If Thwonk resolves first: Unit is stunned, then Flash moves it, unit stays stunned
• If Flash resolves first: Unit is no longer a legal target, Thwonk whiffs

Nuances:

• Once a unit is stunned by Thwonk, moving it with Flash does not remove the stunned status for that turn