Chara

Chara is the main antagonist of the Dusttale AU. They were once a human who lived on the surface who had eventually fell into the Underground and was raised by the Dreemurr Royal Family. Chara was known to be the first human to ever set foot in the Underground. Eventually, Chara grew ill and it would eventually kill them. Chara's dying wish was to be put to rest in the field of Golden Flowers in their hometown. Asriel, the son of Asgore and Toriel would absorb Chara's SOUL and cross the barrier with Chara's lifeless body to put them to rest. When the humans saw Asriel, they blamed him to be responsible for Chara's death, leading to the humans attacking him, eventually causing Asriel to die when he returned to the Underground.

After Asriel died, whatever remained of Chara's SOUL would be in the Underground, waiting for someone take to control over. When Frisk arrived in the Underground, Chara saw this as their opportunity to take control over them. After the Pacifist Timeline was completed, Chara possessed Frisk and began hundreds of Genocide Routes. During the 327th run, Sans began killing monsters before Chara could get to them and gain more LV. This would lead to Sans trying to kill Chara in this timeline.

Personality
Chara seemed to once be a caring person, however, they never really seemed to care about humanity. After their death, they became obsessed with the idea on killing all life. Chara now seems to be a genocidal megalomaniac.

Chara's Theme

 * Megalo Strike Back

Trivia

 * Chara's favorite food seems to be chocolate.
 * There is a debate on Chara if they're actually evil.
 * Chara can sometimes be mistaken to be the protagonist of the AU, but this is not the case since Chara is responsible for most of the events in Dusttale.
 * Chara's gender is up to the fandom's choice.
 * It is unknown who Chara's real parents are, or what they were like.
 * It is often presumed that Chara had an abusive family that didn't care about them, possibly leading to what caused Chara to leave their home.
 * It could be possible that Chara was actually born several decades before the events of Undertale, making them mentally an adult.
 * Chara may have been responsible for their own death.