Games like Mythos
Games like Mythos include The Bazaar, 9 Kings, Slay the Spire 2, Vampire Crawlers: The Turbo Wildcard from Vampire Survivors, and Slay the Spire. We matched them by the tags players give Mythos on Steam (Card Battler, Strategy, Auto Battler, PvE, and Action): closest matches first, and among equally close ones the better-known games.

The Bazaar
Shared: Strategy · Auto Battler · Card Battler

9 Kings
Shared: Strategy · Auto Battler · Card Game

Slay the Spire 2
Shared: Strategy · Card Game · Card Battler

Vampire Crawlers: The Turbo Wildcard from Vampire Survivors
Shared: Card Battler · Strategy · Action

Slay the Spire
Shared: Card Battler · Strategy · Card Game

Oaken Tower
Shared: Strategy · Auto Battler · Card Battler

Magic: The Gathering Arena
Shared: Strategy · Card Game · PvP

GWENT: The Witcher Card Game
Shared: Strategy · Card Game · PvP

Super Fantasy Kingdom
Shared: Strategy · Auto Battler · Card Battler

Balatro
Shared: Strategy · Card Game · Deckbuilding

Monster Train
Shared: Card Battler · Card Game · Strategy

Inscryption
Shared: Card Battler · Card Game · Strategy

He is Coming
Shared: Strategy · Auto Battler · Card Game

Yu-Gi-Oh! Legacy of the Duelist
Shared: Card Battler · Card Game · Strategy

Shadowverse: Worlds Beyond
Shared: Card Battler · PvP · Strategy

Backpack Battles
Shared: Auto Battler · Strategy · PvP

One Turn Kill
Shared: Strategy · Card Battler · Card Game

Legion TD 2 - Multiplayer Tower Defense
Shared: Auto Battler · Strategy · PvP

Morimens
Shared: Card Battler · PvP · Strategy

Ratropolis
Shared: Card Battler · Strategy · 2D

Library Of Ruina
Shared: Strategy · Card Game · Deckbuilding

Armello
Shared: PvP · Strategy · Board Game

GWENT: Rogue Mage (Single-Player Expansion)
Shared: Strategy · Card Battler · Board Game

Batomon Showdown
Shared: Auto Battler · Strategy · Card Battler