Dweller-In-Darkness (Marvel Cinematic Universe)

Dweller-In-Darkness is the main antagonist of the 2021 Marvel Cinematic Universe film Shang-Chi and the Legend of the Ten Rings. He is a Soul Eater who tricks Xu Wenwu into thinking that his deceased wife was the one who was trapped behind the seal in order to escape, and succeeded his plans as well the Soul Eaters's leader, and boss.

Shang-Chi and the Legend of the Ten Rings
Dweller-In-Darkness is first seen when he is released from the Seal, then he try to succeeded his plans but Shang-Chi stop, and defeated him by using the ten rings.

Personality
Dweller-In-Darkness was intelligent, and manipulative. It used voice mimicry to lure people to it's prison, using the voices of their loved ones to get them to free it given that he did tricked Xu Wenwu, Dweller was also incredibly destructive, seeking to consume all the souls it could to gain more power.

Trivia

 * Dweller is thought to be the overarching and final antagonist of the film but this is not true, even through Xu Wenwu appears more than Dweller, Dweller was a much bigger threat to the characters in the film, having bigger plans than anyone, and trick Xu Wenwu into thinking that his deceased wife is trapped behind the seal in order to esacpe, and succeeded his plans which cause the plot of the film.
 * In the comics, the Dweller-in-Darkness is a Fear Lord and an enemy of Doctor Strange.