Kahil Grigesh is only a name yet. It first appeared in Nitara's Armageddon bio but back in MKDA, the original idea was to have a female and a male vampire. Of course, due to lack of time, only one of them made the cut. But many MK characters that were created for MKDA have seen the day later on in MKD mostly.
Kahil was, based on that bio the first wielder of Datusha, a sword existing to slay vampires that Ashrah wields today in MK. It was also said that after killing a lot of his fellow vamps with the sword, Kahil Grigesh brought the weapon with him in the Netherealm and committed Hara Kiri to atone for his sin and make the sword disappear. But the nightmarish weapon is finally back for vampire blood.