Games like Lucius III
Games like Lucius III include Lucius, CARRION, Outlast 2, Lucius II, and Scorn. We matched them by the tags players give Lucius III on Steam (Adventure, Gore, Villain Protagonist, Violent, and Horror): closest matches first, and among equally close ones the better-known games.

Lucius
Shared: Adventure · Villain Protagonist · Gore

CARRION
Shared: Gore · Villain Protagonist · Horror

Outlast 2
Shared: Horror · Gore · Violent

Lucius II
Shared: Gore · Villain Protagonist · Horror

Scorn
Shared: Gore · Horror · Adventure

Outlast
Shared: Horror · Gore · Adventure

Clive Barker's Hellraiser: Revival
Shared: Gore · Horror · Adventure

Amnesia: The Dark Descent
Shared: Gore · Horror · Adventure

Little Nightmares II
Shared: Adventure · Horror · Singleplayer

Little Nightmares
Shared: Adventure · Horror · Singleplayer

Poppy Playtime
Shared: Horror · Singleplayer · Puzzle

Fran Bow
Shared: Adventure · Horror · Indie

Resident Evil 7 Biohazard
Shared: Horror · Gore · Singleplayer

Sally Face - Episode One
Shared: Adventure · Horror · Indie

Resident Evil 2
Shared: Horror · Gore · Singleplayer

The Evil Within 2
Shared: Horror · Gore · Adventure

SOMA
Shared: Horror · Gore · Dark

Manhunt
Shared: Gore · Violent · Horror

Resident Evil Village
Shared: Horror · Gore · Singleplayer

The Medium
Shared: Adventure · Horror · Psychological Horror

MADiSON
Shared: Horror · Adventure · Dark

Tiny Bunny
Shared: Horror · Gore · Dark

Kindergarten 2
Shared: Adventure · Gore · Violent

DOOM Eternal
Shared: Gore · Violent · Demons