Complex sentence: In 1986, DC Comics published Crisis on Infinite Earths, a 12 issue series designed to clean up and establish a new continuity for DC, affecting not only Superman, but all of the DC Comic Characters.
Split into simpler sentences: In 1986, DC Comics published Crisis on Infinite Earths, a 12 issue series designed to clean up DC's continuity. This affected not only Superman, but all of the DC Comic Characters.