Darth Maul and General Grievous vs Sidious

they also thought that revan was a Sith'ari

GG Killed alot I got this from Wikipedia
Jedi Place of death
Adi Gallia Boz Pity
B'dard Tone Belsus
B'ink Utrila Coruscant
Daakman Barrek Hypori
Firkrann Xagobah
Flint Torul Over Belderone
Flynn Kybo Belsus
Foul Moudama Coruscant
Jmmaar Vandos
L'lacielo Sageon Over Coruscant
Nystammall Tovarskl
Pablo-Jill Over Coruscant
Quarmall Location unknown
Puroth Tovarskl
Roron Corobb Coruscant
Roth-Del Masona Coruscant
Sha'a Gi Hypori
Soon Baytes Boz Pity
Tarr Seirr Hypori
T'chooka D'oon Vandos
Ur-Sema Du Geonosis
Waldan Bridger Togoria
Zephata'ru'tor Over Nadiem
An unknown Jedi (first Jedi kill) Kalee or Tovarskl
26 unknown Jedi Over Belderone
An unknown number of Jedi Geonosis
An unknown number of Jedi Location(s) unknown
An unknown Dark Jedi Dica or Necropolis

Adas was believed to be the sith'ari (overlord) and was actually given the title, however I doubt it was him. Either Revan or Anakin imo.

Revan and Anakin ARE the sith'ari, it says so in the site

Maul and GG would destroy Sids. They would have a good chance normally, so when you take away Sidious's force powers, it is just too much.

BTW, is Lord Dragonfire Blak Fox?