Janemba (pre-Transformation) vs...

[Fantastische Hure]

Super-Perfect Cell

SSj2 Gohan (Cell-Games)

Majin Vegeta

SSj2 Goku/Majin Vegeta (together)

Gray Boo

Kid Boo

 

[Six Trails]

Well, if you think Evil Boo's Ki on the Lookout that made Piccolo worry for Gotenks' chances was included in Goku's statement about Janemba being the greatest Ki that he's ever felt, then Janemba would clear.

 

[Captain Cadaver]

It all depends on how you interoperate Movie 12's timeline. Depending on that, Fat Janemba could go from being above Fat Boo to being able SSJ Gotenks (post). In the high end scenario, he clears the gauntlet easily. In the low end scenario, he gets up to at least Pure Boo.

 

[Super Saiyan Overlord1007]

I put Fat Janemba above Majin Buu (When he fought Goku). I can see Pure Evil Majin Buu beating him, but Kid Buu definitely flattens him.

 

[Disasters GoOn]

Fat Janemba is pretty much a rehash of Fat Boo, so he's low-SSj3-tier IMO.

In other words, squashes the first four like a little bug, somewhat easily takes out Gray Boo, and then proceeds to lose against Chibi Boo.

 

[Zippy]

Stops at kid buu