If Fiora, Victorious is defending alone on Forbidding Wastes while equipped with an item that gives +2 Might, does she retain her Mighty ability?

Ruling: Yes. Fiora retains her Mighty ability and ends with 5 Might. The Arithmetic Layer system ensures that all increases to Might are applied before all decreases, regardless of when effects become active.

Sequence:

• Start with base Might of 4
• Apply all increases first: +2 from equipment and +1 from Shield (granted by being Mighty) = 7 Might
• Apply all decreases last: -2 from Forbidding Wastes = 5 Might
• Final Might is 5, so she remains Mighty and keeps Deflect, Ganking, and Shield

Nuances:

• The order of increases before decreases is mandated by the layer system, not by timestamps or the order effects became active.
• Because she starts Mighty (6 Might from base + equipment), Shield is already active before becoming a solo defender, and its +1 Might bonus is included in the calculation.