General Grievous

"'If I can’t kill your friends right now, I’ll give them something to fear…'""— Grievous as he begins approaching Hat Kid"

Background
A proud Kaleesh warrior, Grievous was once an organic soldier on the losing side of a war on his planet, despite his expertise in battle and becoming a sort of demigod among his people. Desperate to end the war on his terms, he turned to the Separatists Confederacy for after his enemies managed to get the Galactic Republic to help in their war efforts. However, one fateful night, the shuttle Grievous was riding in exploded due to a hidden bomb placed upon the vessel, killing almost everyone on board and leaving the General in critical condition. The Separatists were able to revive him into a cyborg and was trained to use a Lightsaber by Count Dooku.

Grievous became Supreme Commander of the Separatist Army, with his first mission being leading the droid army in the Battle of Hypori, during which he was able to kill 3 out of the 7 Jedi and severely injuring three of them. From there, he quickly picked up a reputation as a tactical, yet merciless brute, killing many Jedi and leading the Separatist to victory multiple times. During the Battle of Coruscant, Grievous was tasked to kidnap Chancellor Palpatine and despite opposition from the Republic, he was able to complete his mission, brutally slaughtering four Jedi protectors as well as multiple Clone Troopers, only really finding a challenge in Mace Windu, who was able to injure Grievous as he was retreating with the Chancellor. Around this point in time, a collision between the Star Wars universe and Starcrossing took place, transporting the General into the dimensional amalgamation among many others.