Star Wars: The Real Reason Palpatine's Face Changes In Revenge Of The Sith

screenrant.com:

Palpatine claims he is left disfigured after his battle with Mace Windu in Star Wars: Episode III — Revenge of the Sith, but is there a different reason why his face changes? First released domestically on May 19th, 2005, Star Wars: Episode III- Revenge of the Sith is widely celebrated as the best of the Star Wars prequel trilogy movies, owing no small part to its more challenging subject matter and dark undertones. The most poignant of these is undoubtedly the Faustian-style bargain Anakin Skywalker (Hayden Christensen) strikes with Palpatine/Darth Sidious (Ian McDiarmid) to save Padmé Amidala (Natalie Portman) after being emotionally manipulated by Palpatine in multiple Revenge of the Sith scenes.

Canonically, the events of Revenge of the Sith can be considered the Sith's crowning achievement, with Palpatine's machinations coming to triumphant fruition as the Jedi are nearly exterminated, and the First Galactic Empire is formed. Of central importance to Palpatine's overarching plan is his manipulation of Anakin, who, after seeing his mentor laying prostrate at Mace Windu's (Samuel L. Jackson) feet, attacks the Jedi master and turns to the dark side. Palpatine then uses this brutal encounter with Windu to unfurl the rest of his political plans, asserting that "the attack on my life has left me scarred and deformed" as he dissolves the Senate.

Related: The Obi-Wan Series Must Make Sure Vader's Story Doesn't Overshadow Kenobi

While on a tertiary level, Palpatine's face appears to melt due to his clash with Mace Windu, several scenes in Star Wars: Revenge of the Sith prove that this is not the case. The end of George Lucas' prequel trilogy instead proves that Palpatine's face changes as part of his plan to manipulate