Suggestions by @https17walten

Jennifer Garner

as Tamayo in Demon Slayer: fancast for demons

Score: +1

Noah Schnapp

as Zohakuten in Demon Slayer: fancast for demons

Score: +1

Louis Partridge

as Aizetsu in Demon Slayer: fancast for demons

Score: +1

Jacob Elordi

as Karaku in Demon Slayer: fancast for demons

Score: +1

Ruairí O'Connor

as Urogi in Demon Slayer: fancast for demons

Score: +1

Robert Pattinson

as Sekido in Demon Slayer: fancast for demons

Score: +1

Alex Wolff

as Gyutaro in Demon Slayer: fancast for demons

Score: +1

Evan Peters

as Akaza in Demon Slayer: fancast for demons

Score: +1

Björn Andrésen

as Hantengu in Demon Slayer: fancast for demons

Score: +2

Jeff Ward

as Kokushibo in Demon Slayer: fancast for demons

Score: +1

Timothée Chalamet

as Kaigaku in Demon Slayer: fancast for demons

Score: +1

Morgan Davies

as Fake spider brother in Demon Slayer: fancast for demons

Score: +1

Arata Mackenyu

as Doma in Demon Slayer: fancast for demons

Score: +1

Peter Gadiot

as Kyogai in Demon Slayer: fancast for demons

Score: +1

Gong Li

as Nakime in Demon Slayer: fancast for demons

Score: +1

Natalie Portman

as Fake spider mom in Demon Slayer: fancast for demons

Score: +1

Dwayne Johnson

as Fake spider dad in Demon Slayer: fancast for demons

Score: +1

Kristen Stewart

as Daki in Demon Slayer: fancast for demons

Score: +2

Javier Botet

as Gyokko in Demon Slayer: fancast for demons

Score: +1

Sabrina Carpenter

as Mitsuri Kanroji in Kimetsu No Yaiba/Demon Slayer

Score: -1