Sentai Villain Decay

I would like to write on Sentai villains I believe suffered from villain decay:

Baraba- I think he did suffer from villain decay ever since Kiros showed up.  Then again, I never liked him as a bad guy anyway.  He was a scoffing villain.

Zulten- He really went from bad to worse ever since the Nagare Bouma appeared.  Fortunately he's not as dumb as Bookback from Zyuranger was who was already decayed from the start.  So how did it work?  He remained hidden most of the time and only showed up whenever the writers felt like it.  Shigoki Bouma turned him into a fart machine in episode 33.  In episode 37, he created a fake Zulten but failed.  In episode 39, he was forced to side with the Nagare Bouma after he could not help his master Ragorn.  Overall, he was just another pushover.  However he's not as dumb as Bookback.

Garoa- In Fiveman, he started off as an extremely vicious character but he later suffered from becoming comic relief like Monster was.  So where do I start?  Well Garoa after introducing the hybrid monsters went into a series of toning down of parts like when he was dismissed for being unable to defeat the Fivemen.  He did become a janitor for some time.  His only redeeming part after his decay was when he created the Big Garoan and placed the Fivemen in deep doo doo which made him the vicious Garoa once more only to later die what I consider a lame death.  He should have been taken out by the Fivemen in the finale before they ultimately won against Vulgyre.

General Tenpou- Though he had a significant part as he was higher than Shaddam and he was Gorma XV's right hand man, he was however easily disposed of and his part really diminished throughout the series.  Shaddam had more parts than he had.