If Unsung Hero dies after being stupefied (reducing its attack from 5 to 4), does its mighty deathknell trigger?

Ruling: The deathknell triggers, but you won't draw the 2 cards because the mighty condition is checked when the deathknell resolves, and at 4 attack the unit is not mighty.

Sequence:

• Unsung Hero dies with 4 attack (after being stupefied)
• The deathknell ability triggers ("When I die")
• Upon resolution, check if the unit was mighty
• Since it has 4 attack, it is not mighty, so the "draw 2" effect does not happen

Nuances:

• The trigger condition is everything up to the first comma ("When I die"), while the mighty check is part of the effect
• The ability always triggers when the unit dies, regardless of mighty status