As seen in recent weeks, Killer Kross made his debut on NXT by attacking Tommaso Ciampa. He is using the ring name “Karrion Kross”. According to Fightful, the name change came from Kross himself and not WWE.
For what it’s worth, the word “carrion” is decaying flesh of dead animals. “Kharon” in Greek mythology is the ferryman who takes souls to the land of the dead. Kross has a tattoo that says “Kheiron” on his back.
WWE officials were reportedly open to using the word “Killer” on TV despite rumors to the contrary.