DSR

The Dark Silver Ranger, aka DSR, is a bounty hunter from Earth-4 sent to take down Kuroninja, while he was busy with the Battle of the Kyuranger Fanfictions.

Biography
3 evil Kuroninjas known as Anti-Kuroninja, Akuroninja, and Cyber Kuroninja decided to team up to take down Kuroninja of Earth-1. Their alliance unlocked the Dark Kyutama, which they gave to bounty hunter known as Naga. Naga then became the Dark Silver Ranger and proceeded to hunt down Kuroninja. Kuroninja then felt like he was being watched and battled against him while writing his blog at the same time.

Behind the scenes
This is actually the Earth-4 counterpart of HebitsukaiSilver of Earth-9. Councidentally, HebitsukaiSilver became the evil HebitsukaiMetal in Episode 26 of Kyuranger.