10. Shiro Kazanki from Ryuki
9. Bishop from Kiva
8. Great Leader of Shocker from Kamen Rider
7. Caucasus Undead from Blade
This is my favorite Undead of the series as he was the first King and he was strong! He always wanted to make trouble as he stole Hajime's cards and gives them to Mutsuki for his own pleasure. He posed as a teenage boy and could protect himself with a shield he can summon. In his Undead form he has hard defense like his shield and Kenzaki could barely fight him. Soon though he gets his cards as well and makes Kenzaki realize that the cards don't give him powers as he defeats him with his own strength. He accepts his defeat as he warns Kenzaki about his powers before he is sealed. A great villain that may seem annoying, but in the end he pushed the hero to the highest point and he accepts defeat which is nice to see before he dies.
6. Aki Sawada from Faiz
5. Shadowmoon from Black and Black RX
Mostly any rider fan I know will always talk about Shadowmoon as he is very iconic in the franchise. To many fans he is the first dark rider as he fought against Kotaro. He was actually his step brother Nobuhiko who goes through the full process as his humanity has been trashed as Shadowmoon took over. He was a strong rival as he was always a challenge for Kotaro. He even appears in Black RX, but has lost his memory as he works with Crisis soon, but goes on his own then. In the end Kotaro deals with the fact that he is not Nobuhiko and attempts to stop Shadowmoon no matter what. In RX it seemed that Nobuhiko could have awoke once more to do an act of heroism before he died. I can see why he is remembered greatly as he was a strong villain who soon has a harsh end as Nobuhiko himself is lost.
4. Kirihiko Sudo from Double
3. N-Daguva-Zeba from Kuuga
2. Takeshi Asakura from Ryuki
Everyone knows this rider from Ryuki as he progressed the battle greatly and that's why he was chosen by Kenzaki. He is a criminal who has repeated crimes mostly murder as he was crazy. When he became a rider he took out Gai with no problem and more riders. What makes him great is how crazy he is and the series does that great as he had a good episode arc showing that. Barely anything could take him down as he killed four riders! In the end he was killed by the police as they shot him to death on sight. Asakura is a crazy man who could barely go down and you know that the only thing that does stop you is a whole hoard of cops.
1. Dr. Maki from OOO