There has been some confusions about characters for years, many PR fans confuse how a Power Rangers character was portrayed versus their Super Sentai counterpart, hence believing that the Super Sentai character was portrayed in the same manner. This was all brought up because of the recent picture from the 199 heroes film revealing with Extra Heroes are counted and also the recent poll where most of the fans picked Zyuranger characters as the best of the 1990's and other fans disliking the picks.
Many people are confused to why VRV Master is not considered one of the extra heroes, or not even a sixth ranger. VRV Master was the counterpart for Phantom Ranger but in reality, VRV Master only appeared for a few episodes, and a minor mentor. Power Rangers Turbo and Space just built a big character (Phantom Ranger) around a little big of footage, hence the confusion.
Hyuuga is being called by fans, including me, as BullBlack and he is one of the Extra heroes. Many consider him a sixth as he was sold as a sixth in both Japan and America. I still see him as a Sixth, if GoseiKnight is a sixth, then he's a sixth. They have common threads to the main five and have big bulky armor.
"KuroKishi (Black Knight) would be the catch-all term for both, but I think BullBlack just has that ring to it. Technically, it's "KuroKishi Hyuuga" but then we're really splitting hairs."
The recent poll I put to pick the best of the 1990's and most of the fans picked Zyuranger characters (well, Gai of Jetman beat Goushi of Zyuranger). Other fans disliked these picks. I don't mind. But maybe there is a confusion that Zyuranger is just like MMPR. There are Sentai fans that consider Zyuranger a bad uneven series. It indeed is strange. But to tell you the truth, when I watch it, I have this strong feeling of nostalgia. Especially the scenes with Rita and her crew, I feel mystified. Maybe because we grew up with MMPR, that we see Zyuranger with beer goggles as well, or milk goggles as it were.