In the Triggered By tab specifically, there should be two additional checkboxes:
1) All Enemies Defeated: As the name implies, defeating all enemies also can act as a trigger for this combo (easy custom shutters anyone?)
2) Applies to EWeapons: A checkbox that makes it so whatever weapons are checked, it applies to the EWeapon (enemy weapon) version. So for example, if you have arrow checked, it will also trigger if an enemy's arrow hits it.
Also, moves the "Kill Wpn" flag to the Triggered By tab so that this can apply to all combo types, not just the generic one, & it just makes more sense here.