Onslaught is a fictional character appearing in Marvel Comics. Created by writer Scott Lobdell and artist Mark Bagley, Onslaught first appeared in 1996. He is a powerful entity formed from the consciousness of Professor X and Magneto, combining their abilities and ideologies. Onslaught possesses immense telepathic and telekinetic powers, making him one of the most formidable villains in the Marvel Universe. The character is often depicted as a major threat to the X-Men and the broader superhero community. His storyline includes significant events like the Onslaught Saga, which led to the temporary disappearance of many heroes. Onslaught's complex nature reflects themes of good versus evil, as he embodies the darker aspects of both X-Men leaders.