If a unit with 4 Might takes 3 damage from Hextech Ray, then has its Might reduced by 1 from Stupefy, does it die?

Ruling: Yes, the unit dies. Units die when they have damage marked on them greater than or equal to their Might.

Sequence:

• Unit with 4 Might takes 3 damage from Hextech Ray (3 damage marked, 4 Might - survives)
• Stupefy reduces Might by 1 (3 damage marked, 3 Might - now equals)
• Unit dies in the cleanup that follows Stupefy resolving

Nuances:

• The damage marked on the unit remains constant; only the Might value changes
• Death occurs when damage marked is greater than OR equal to Might