Hardest Boss?

[Kyubey the Jabroni]

The place to discuss the bosses that would make you break your controller in anger! (Naming two similar bosses aren't cheating, but you need to tell why they're similar)
I'd say Primal Dialga (PMD2)/Jasper Batt Jr. (NMH2) were the biggest jerk moves designed. Primal Dialga had an semi-instant kill move (It likely dealt more damage then you or your partner sported) that would destroy you after an annoying dungeon which will sap you of your items, and Jasper Batt Jr. would wouldpunch you through a window, instantly killing you. The kicker? They both spam the attack, forcing you to die more often then you killing them. The only difference is that Primal Dialga was cool and was justified (he went insane), Jasper Batt Jr is a person you want to murder.

 

[Lord Rathan]

Absolute Virtue.

 

[jianmingyong]

I don't find Primal Dialga insane but Darkrai insane as you have to beat 5 other distractor while the boss would use moves that hit all players making it insane. Given that you are also forced to have Cresselia which again WASTE MY reviver seeds like 10? No 20? He died every 2 to 3 hits from the boss or distractors.

Whats more, the boss can speed up everytime it hit making it impossible for a normal player who can't take ridiculous insanity to complete the side game. So I would say darkrai from PMD2 are the most annoying and the most insane ever.

 

[Kyubey the Jabroni]

Absolute Virtue.

What's funny is Squenix actually made a video on beating them, then patched the game immediately.

 

[Lilligant]

F Zero GX, Deathborne, Hardest Difficulty, 25+ second headstart. It has been done, but it was pretty close, plus the guy that did it gave him a 26 second headstart, and is a speed runner.

 

[Conquest]

Shao Kah,because well you know

 

[The Omega Gengar]

Well, Barrier Trio was really annoying for me before I got PSI Shield Ω. Or was it Defense Up Ω? Dunno.
I'll think of better ones later.