I am defending a battlefield alone with Fiora, Peerless. My opponent attacks it with a 1 unit. My legend is Master Yi, Wuju Bladesman. On the when I defend trigger, I use Disciple on my Fiora. I let it resolve then in the showdown I play an ambush unit to the same battlefield. What is the might of my Fiora?

To determine the final Might of your Fiora, Peerless, we must follow the layering rules for static bonuses and the resolution order of triggered abilities and spells during a combat showdown.

Final Might Calculation

Your Fiora, Peerless will have 12 Might for this combat.

Sequence of Events

1. Passive Application: Your Master Yi, Wuju Bladesman legend has a passive ability: "While a friendly unit defends alone, it gets +2 might." As soon as Fiora is designated as the lone defender, her base Might of 3 receives this +2 bonus, resulting in 5 Might.
2. Initial Chain: Fiora’s "When I defend" trigger is placed on the Initial Chain.
3. Reaction (Discipline): In response to the trigger, you play Discipline ([Reaction]).
   • Discipline grants Fiora +2 Might. This is an Arithmetic layer increase.
   • Fiora's current Might becomes: 3 (base) + 2 (Master Yi) + 2 (Discipline) = 7 Might.
4. Resolution of Initial Chain:
   • Discipline resolves first (LIFO).
   • Fiora’s "When I defend" trigger resolves, doubling her current Might (7). Her Might becomes 14.
5. Ambush: You play an Ambush unit. Because Fiora is no longer defending alone, the +2 Might bonus from Master Yi ceases to apply (Rule 741.1). However, because Fiora's doubling trigger has already resolved, the +7 Might gained from that effect remains for the duration of the combat. Her final Might is 14 - 2 = 12 Might.

Why this works

• Layering: Passive bonuses (like Master Yi's +2) and spells (like Discipline's +2) are applied in the Arithmetic layer.
• Trigger vs. Passive: As established in RiftJudge FAQ #10960 and #11088, triggered abilities that double Might do so based on the current stat at the time of resolution. Once the trigger resolves, that doubled value is locked in for the duration of the combat, but conditional passive bonuses (like Master Yi's) continue to be monitored and will be removed if the conditions are no longer met.

This interpretation is based on the rules governing passive application (Arithmetic Layer) and the standard resolution order of the Initial Chain as defined in the Showdown Flow.