Talk:Luden's Echo/@comment-4636093-20150228172532/@comment-4022742-20150303082628

It works like a "Spell Buff" for the spell you use to trigger it, and it goes up to 4 targets. If your spell only hits 2, it'll only deal damage to 2, not 4.

That being said, if your bonus damage kills the target while you cast Q, it'll follow the same rules as and. For Gangplank and Nasus these items will trigger the bonus effects, giving gold/damage for each minion killed in this manner.