Recently Lux got buffed and received a new effect on her ultimate. Now in addition to its damage (and passive proc/refresh) it also refunds 10/30/50% of the cooldown if it kills an enemy.
How does it work exactly? For example, if I get a double kill with Final Spark will it reduce the cooldown once per Champion, or just once per cast?
Furthermore, does it reduce before or after Cooldown Reduction is taken into account?