Does Leona maintain defender status (and shield bonus) after combat but before Kog'Maw's Deathknell resolves, or does she revert to base Might and die to the Deathknell damage?

Ruling: Leona dies to the Deathknell. The cleanup that kills Kog'Maw also removes defender status, so Leona reverts to 4 Might before Deathknell resolves.

Sequence:

• Combat occurs between Kog'Maw and defending Leona (who has 5 Might with shield)
• Cleanup phase kills Kog'Maw and removes defender status from Leona
• Leona reverts to 4 Might
• Kog'Maw's Deathknell triggers, dealing 4 damage
• Leona dies

Nuances:

• Even if defender status wasn't removed immediately, Leona would eventually die when the shield drops since Kog'Maw's Deathknell damage doesn't heal before combat ends