Mire Blight

• WWizards of the Coast2009-10-01
  Official Ruling
  If Mire Blight’s ability triggers, the creature it was enchanting at that time is the one that will be destroyed when the ability resolves. It doesn’t matter if Mire Blight leaves the battlefield or somehow becomes attached to another creature by that time.
• WWizards of the Coast2009-10-01
  Official Ruling
  Mire Blight’s ability triggers when the enchanted creature is dealt any kind of damage, not just combat damage.

Rulings via Scryfall