If Cithria of Cloudfield (with a buff counter) dies during combat, and Sett Kingpin loses the might buff from Cithria while having lethal damage marked on him, does Sett die?

Ruling: Sett survives. During the Resolution Step, all lethally damaged units are moved to trash simultaneously, then damage is healed. Since Cithria is still present when lethal damage is checked, Sett still has the extra might at that moment. After units are trashed, damage heals before cleanup would check again.

Sequence:

• All units take damage simultaneously during combat
• During Resolution Step, lethally damaged units are identified and moved to trash simultaneously (Cithria would be trashed here, but Sett still has the buff at this moment)
• Damage is healed on remaining units
• Cleanup occurs, but Sett no longer has damage marked on him

Nuances:

• Passive abilities are checked continuously and are always active while the unit is on the board
• The game only kills units during cleanup and resolution step, not between these phases
• This sequencing prevents units from dying in the middle of resolutions or between applying continuous effects