Lord Deathstrike was an assassin who's an antagonist in the original Big Hero 6 comic book series.
Big Hero 6
Wolverine Vs. the X-men
In the Wolverine Vs. the X-men story arc, the Red Right Hand gave Deathstrike the task of killing Mystique. Mystique eventually does get killed, but it is the Wolverine who killed her and not Lord Deathstrike.
Back in Japan
Later on, in the Back in Japan story arc, Wilson Fisk hires Deathstrike after learning that Azuma Goda was responsible for the Yakuza/Hand War. When Deathstrike saw that Azuma was on the roof deck, he proceeded to shoot him in the head. It's revealed, however, that it was really Mystique disguised as Goda, and she and her would-be-assassin then engage in a fight. Sabretooth then comes and asks for Deathstrike to work for him. Sabretooth then takes Deathstrike and Mystique to a place in which the East Asian families were meeting, and they proceed to slaughter everyone there. Sabretooth was then made the ilegitimate leader of the Asian crime families.
Lord Deathstrike's most recent job was to assassinate Raizo Kodo and the Forgiven. Deathstrike later found himself in conflict with the vampire, Jubilee. After he was defeated by the young vampire, Jubilee attempted to feed on his blood. She's only stopped after Raizo and Storm remind her about her pledge to not feed on human blood. She then lets the assassin go, and he then bows to her before leaving.
Powers and Abilities
Deathstrike has many eccentric abilities at his disposal. He is known for having bullets that are able to return to him with the press of a button, and he is also able to run up the sides of buildings, thanks to his well-equipped shoes. His mask also serves as a means of protecting himself from harm, and it also helps to enhance his vision.
Big Hero 6