system
Given the following post, respond as if you're commenting on Reddit:
human
[Star Wars] How much did Savage Opress's intelligence decrease after being transformed and why was that acceptable?

Wouldn't a smarter assassin be more useful?
gpt
Opress wasn't a tactical assassin, he was a lethal weapon. Point him at the threat and watch him bulldoze through it. 

His raw strength and ability to overpower most resistance was something Dooku was heavily interested in, which is why the Night Sisters used him for their plan. If he was smarter he might have considered betraying Dooku or the Night Sisters (mostly Ventress) as soon as a better opportunity came along. It is Sith nature to overthrow your master after all, so as long as Opress could be a deadly weapon smart enough to outplay his overpowered opponents and survive in battle but *not* smart enough to scheme and make power plays, he fulfilled his use for all of his masters. Dooku, the Night Sisters, Ventress, Maul, he fulfilled his purpose for all of them. Well, besides actually managing to kill Dooku/Ventress and or help Maul overthrow Sidious.  

He also wasn't dumbed down so much as hypnotised into a ferocious mindset where battle and fulfilling orders was his core motivation. He still had some personal quirks like his emotional devotion to  Mother Talzan and his brother Maul, but overall he just became more of a battle-hardened warrior than a man who *happens* to fight. Much more receptive to orders and brutality that way.