- "All shall die. I shall live."
- ―Dev Asur's catchphrase[src]
Dev Asur is an evil version of Kamen Rider Dev. Unlike Dev, Dev Asur is powered by demonic energies and malice, and he aims to 'purge' the multiverse and defeat his alternate versions.
Dev Asur was once a good demon who received his powers from the Tridev in a similar way Raj Singh did in the modern times. However, because of the interference of Bitroids in his world, he went rogue. Dev Asur began to travel through space-time and attempted to merge with a version of Kamen Rider Dev, ultimately merging with the one from his world and becoming Kamen Rider Dev Asur.
- "Creation. Preservation. Destruction."
- ―Transformation announcement from the Trinity Driver[src]
- Rider Height: 198.5 cm
- Rider Weight: 99.0 kg
- Punching Power: Immeasurable (Variable as per requirement)
- Kicking Power: Immeasurable (Variable as per requirement)
- Maximum Jump Height: Immeasurable (Variable as per requirement)
- Maximum Running Speed: Immeasurable (Variable as per requirement)
- Asur (असुर) means Demon in Hindi/Sanskrit.
- Dev Asur's name was originally going to be Dev Darkness.
- In the original design, Dev Asur did not have the Trinity Driver on his waist. It was added on suggestion by many readers.