Does Ahri's legend ability affect only one attacking unit or all attacking units in a showdown?

Ruling: Ahri's legend ability triggers separately for each attacking enemy unit. If 5 units attack, all 5 units get -1.

Sequence:

• When multiple units attack, the ability triggers once for each attacking unit
• The ability goes on the chain separately for each attacker
• Each attacking unit receives the -1 effect

Nuances:

• The singular wording "when an enemy unit attacks" does not limit it to one trigger - it triggers individually for each unit that attacks
• The ability does not target (no choice is made)
• There is a different blue champion version of Ahri (Ahri, Inquisitive) with a similar ability that only affects a single unit, which sometimes causes confusion