HK-47 will be reworked, he'll get the OR tag, and his rework will include a Deathmark mechanic of some kind. I mean, it's not just in the kits for these new characters (Jedi Revan included), it's in the lore of HK:
"My assassination functions are currently non-functional, having been de-activated by the meatbag Yuka Laka on Tatooine. Were they functional, you as my master would be able to specify a target and I would operate independently to the best of my ability to terminate it." --HK-47, Knights of the Old Republic
I could see HK's rework including a unique ability (maybe called "Assassination Functions") that grants a special ability to whomever is in the leader slot, allowing them to inflict Deathmark on any enemy for X turns. Or something simpler like HK just applying Deathmark with his special.
