If a 7 might unit has 6 damage counters on it and then Stupefy reduces its might to 6, does it die immediately upon Stupefy's resolution, preventing further actions targeting it?

Ruling: When Stupefy resolves and reduces the unit's might to 6, the game recognizes during cleanup that the 6 might unit has 6 damage marked on it and kills it. The dead unit cannot be targeted by subsequent cards like Cleave.

Sequence:

• Hextech Ray applies 3 damage (first focus)
• Hextech Ray applies 3 more damage (second focus)
• Stupefy reduces might from 7 to 6 (third focus)
• After Stupefy resolves, cleanup occurs and the unit dies
• The unit is no longer a legal target for cards like Cleave

Nuances:

• A showdown does not immediately end if one side no longer has units; both players can still use focus to start chains
• If there are no units on both sides at the end of the showdown phase, the combat damage phase is skipped (important for cards like Tryndamere that deal excess damage)