Takamura is always the strongest in my opinion, regardless of Sakamoto being in Prime or not. Takamura's hype is just better. Sakamoto is seen as the greatest assassin, whilst Takamura is seen as an entity of bloodlust. Slur fought Prime Sakamoto but runs away from Takamura.
Anyways in the past:-
- Takamura
- Prime Sakamoto
- Nagumo/Kanaguri
- Prime Yotsumaru
- Shishiba
- Osaragi
- Hyou
Current:-
Same but Slim Sakamoto (no killing) and current Yotsumaru is like low Order lvl.