He did early on but faded into the background later in the series. It's worth noting he was not at all portrayed as the cowardly idiot his Classics bio makes him out to be. On the contrary he was a formidable fighter who once called Hydron a coward simply because he was dodging Karatti's attacks instead of fighting him head on. A smart tactic on Hydron's part because Karatti had previously shown himself to nearly a match for He-Man in hand to hand combat. he once knocked He-Man's sword from his hand with karate chops. (though He-Man also once blocked a blow with the sword which hurt Karatti's hand)
During the Mutant's occupation of Primus it was mentioned that Karatti had taken control of Serus (Hydron's underwater home city) this happened off screen though.
An interesting moment that showed off Karatti's intelligence was when he was able to expose He-Man disguised as a Mutant trooper by noticing the only slightly off behavior