If my opponent plays Cull the Weak and I choose to kill my Irelia, Fervent, does she get +1 Might from her ability?

Ruling: No, Irelia, Fervent does not get the +1 Might bonus when killed by Cull the Weak.

Nuances:

• Cull the Weak uses the structure "Each player kills a unit they control" which does not count as "choosing" or "targeting" for the purpose of triggering abilities like Irelia's
• The choice is made as part of the spell's resolution by multiple players, which is treated differently from a single player choosing or targeting a unit
• Even though players make a choice about which unit to kill, this type of programmatic selection does not trigger "when you choose" abilities