Games like Omnimancer
Games like Omnimancer include Hades II, Hades, Heroes of Hammerwatch II, Death Must Die, and Black Myth: Wukong. We matched them by the tags players give Omnimancer on Steam (RPG, Action Roguelike, Roguelite, Action, and Action RPG): closest matches first, and among equally close ones the better-known games.

Hades II
Shared: Action · Roguelite · Action Roguelike

Hades
Shared: Action Roguelike · Roguelite · Action

Heroes of Hammerwatch II
Shared: RPG · Action Roguelike · Action RPG

Death Must Die
Shared: Action Roguelike · Roguelite · RPG

Black Myth: Wukong
Shared: RPG · Action · Action RPG

Soulstone Survivors
Shared: Action Roguelike · Roguelite · RPG

Halls of Torment
Shared: Action Roguelike · Roguelite · RPG

Streets of Rogue
Shared: Action Roguelike · Roguelite · RPG

Hero Siege
Shared: Action Roguelike · RPG · Action RPG

UnderMine
Shared: Action Roguelike · Roguelite · RPG

Wolcen: Lords of Mayhem
Shared: RPG · Action RPG · Action

Dragon's Dogma 2
Shared: RPG · Action RPG · Action

Sephiria
Shared: Action Roguelike · Roguelite · Roguelike

Vampire Survivors
Shared: Action Roguelike · Roguelite · Roguelike

Gunfire Reborn
Shared: Roguelite · Roguelike · Action Roguelike

Moonlighter
Shared: Roguelite · Action Roguelike · RPG

The Binding of Isaac
Shared: Action Roguelike · Roguelike · Action

Magicraft
Shared: Action Roguelike · Roguelite · RPG

Dead Cells
Shared: Action Roguelike · Roguelike · Adventure

Conquest Dark
Shared: Action · Roguelite · Action Roguelike

Megabonk
Shared: Action Roguelike · Roguelite · Roguelike

Last Epoch
Shared: RPG · Action RPG · Action

Skul: The Hero Slayer
Shared: Action Roguelike · Action · Roguelite

Rogue Legacy
Shared: Action Roguelike · Roguelike · Action