The question comes down to whether or not putting a character in the dead pile is the same as killing it. I know this was clarified at one time on Decipher boards, but I can only find a reference to "killed" in the latest CRD which only talks about killing as reducing a character's vitality to zero or "killing" the character--not too helpful.
But because only killed character go into the dead pile (and are not discarded) I would say the intent was to recognize these characters as killed, thus triggering the combo as you want it to.