The removal or disqualification of an effect is separate from the application of the effect, but still can only be applied once. Example: Fiora, Victorious has printed Might 4 and says “While I'm Mighty, I have Deflect, Ganking, and Shield.” If a player places a buff on Fiora, her Might is increased in the Arithmetic layer, after the layer for Ability-Altering Effects. The Ability-Altering Effect layer is then re-checked and the abilities Deflect, Ganking, and Shield applied. Since each effect has been applied once and there are no other effects to apply, Fiora’s characteristics are finalized as 5 Might with Deflect, Ganking, and Shield. While a buffed Fiora, Victorious is in combat as a defender, an additional +1 Might will be applied in the Arithmetic layer, giving her 6 Might and the 3 keywords. Example: A buffed Fiora, Victorious is in combat as a defender when her buff is removed. Reevaluating the layers in sequence, she no longer gains Deflect, Ganking, and Shield during the Ability-Altering Effect layer, so when the Arithmetic layer is evaluated, neither the buff (which is gone) nor Shield (which she no longer has) apply. She goes directly from 6 Might with three keywords to 4 Might with no keywords.
§ 471.3 Core Rules PDF (officieel)
§ 471 The layers are applied repeatedly until all effects operating on objects have been applied once and no changes have been processed.