A salaryman finds himself trapped in his game avatar as a powerful undead lich with world-conquering potential. It’s the gold standard for 'monster protagonist' stories.
Why it's similar: Both shows feature a pragmatic adult salaryman reincarnated into a powerful being who must navigate a new world using corporate logic and overwhelming force. You'll recognize the same dark humor and the dynamic of an overpowered lead managing loyal, slightly terrified subordinates.
Power comparison: While Tanya uses technology-based magic, Ainz Ooal Gown uses high-tier RPG spells that dwarf everyone else in the world.
Why watch after The Saga Of Tanya The Evil: Watch this if you want to see a protagonist play 4D chess with the world while secretly worrying about their management style.