5 PM My 2 might unit with a buff has a damage counter of 2. If I consume the buff to play Call to glory, does my unit die or does the spell resolve and the unit lives?

Your unit will die.

The Breakdown

1. Playing the Spell: When you play Call to Glory, you must pay its costs. You choose to spend the buff as an additional cost. The moment you pay this cost, the buff is removed from your unit.
2. State Assessment: Your unit began with 2 might (1 base + 1 buff). After spending the buff, your unit is at 1 might. It currently has 2 damage marked on it.
3. The Chain: Call to Glory is now on the chain waiting to resolve. In Riftbound, the game performs a cleanup process to check for lethal damage after any chain item resolves or when priority passes. Because your unit currently has 2 damage and only 1 might, it is at or past its lethal threshold.
4. Why it dies: Because the removal of the buff is an additional cost paid to put the spell on the chain, the unit's might is reduced to 1 before the spell resolves. The unit immediately becomes a target for removal due to having 2 damage marked on it.

Comparison to FAQs

The FAQs you cited (#5865, #3828) involving Call to Glory describe scenarios where the units did not have marked damage at the time the buff was removed. Because those units had no damage, reducing their might did not kill them, allowing the spell to resolve and provide the boost. In your scenario, because your unit has 2 damage marked on it, it meets the requirement for being killed as soon as the buff is removed.

Sequence

1. You initiate the process to play Call to Glory and pay the cost by removing the buff.
2. The unit’s might drops from 2 to 1.
3. The game state sees a unit with 1 might and 2 damage.
4. The unit is killed due to lethal damage.
5. Call to Glory remains on the chain, but its target is no longer in play, causing the spell to fail to resolve.

Note: I could not fully verify this ruling against the retrieved rules.