Can Blade Dancer Irelia's legend ability choose a unit to ready that is already ready, specifically to trigger Irelia, Fervent's +1 might bonus from being chosen?

Ruling: No. Blade Dancer Irelia's legend ability does not "choose" a unit - it only readies a unit. If Irelia, Fervent is already ready, the legend ability cannot target her and will not trigger her +1 might bonus from being chosen.

Sequence: (when Irelia is exhausted and you play Discipline targeting her)

• Discipline targets Irelia, triggering her +1 might from being chosen
• Blade Dancer legend ability triggers, you pay 1 Power to ready Irelia
• Irelia gets +1 might from being readied
• Discipline resolves and Irelia gets +2 might from the spell

Nuances:

• The legend ability's "ready a unit" effect does not count as "choosing" that unit
• If Irelia is already ready, Blade Dancer cannot ready her again and does not trigger any choose-related effects
• Other effects that explicitly "choose" (like Discipline or equipping) do trigger Irelia, Fervent's +1 might bonus