Shin Megami Tensei was the first ever monster collecting game. The core pillars of Shin Megami Tensei are mythological and religious. References. Demon fusions A branching story and being able to negotiate with demons. Many Shin Megami Tensei games are set in a post-apocalyptic world where societies collapse and supernatural forces have taken over. Decisions you make while playing can lead to multiple endings reflecting different moral and ethical paths, such as siding with law, chaos, or even a neutral stance.