[Blade Fang]

My personal favourite potential future demon monsters in DonBrothers series:

- Kaizokuki (Pirate Demon) : Based on Gokaigers. A pirate-themed demon. He is capable to transforms into other demon monsters. I think the Kaizokuki is would be really cool as the new main villain, similar to Hiryu Kakogawa (Another Zi-O) from Kamen Rider Rider Zi-O series.

- Jyukenki (Beast-Fist Demon) : Based on Gekirangers. A kung fu-themed demon. He is capable to access various animal spirits to increase his kung fu fighting style abilities.

- Tokumeiki (Special Ops Demon) : Based on Go-Busters. A special ops-themed demon. He is capable of spying and fighting just like special ops members.

- Miraiki (Future Demon) : Based on Timerangers. A time travel-themed demon. He is capable to time travel to the past and to the future. Probably Miraiki are the final demon monster in DonBrothers series.