Baron Ravanen Kimbolt is a villain in game Witcher 2 Assassins of Kings. He's Foltest's closest cousin and tries to become his successor after his death. He hired bandits to kill his cousin's children Anais and Bussy to eliminate competition for Temerian throne. However Count Maravel ruined his plan.
When Geralt meets him the baron makes no secret how he loathes the witcher and sees him not different from Letho. He gives the witcher a clue that Count Maravel is behind the bandits attacking the royal children. Geralt can discover that the baron tried to kill the children but Maravel had also sent men to kidnap them. Although Boussy was killed, Anais was kidnapped. This gives John Natalis an option to force Kimbolt to support him. If Geralt didn't discover evidences of Kimbolt's crime he gets unpunished, if evidences for Maravel's treason aren't found then Kimbolt gets arrested.
In pursuing their profession, witchers meet individuals both warm and unfriendly, yet they're mostly indifferent to the types with which they must deal, since they themselves can become so unpleasant that only tax collectors and sorceresses can rival them. Be that as it may, Baron Kimbolt made an extremely bad impression on Geralt. He was one of the most powerful individuals in Temeria, yet after Foltest's death his influence grew further. He was known to deal remorselessly with any who stood in his way. The sole thing that could be said in his favor is that he supposedly adored his hunting dogs. Yet he had to leave them behind when he travelled to Loc Muinne, and perhaps that had made him even more discourteous than usual. Why did Geralt put up with him? Well, Kimbolt apparently had something to do with the disappearance of Boussy, Foltest's son.
Did I say "something to do with the disappearance of Boussy"? Forgive me the euphemism. Geralt discovered that Baron Kimbolt had commissioned someone to murder Foltest's son. The baron was intent on assuming the Temerian throne, and the boy simply stood in his way. Kimbolt had planned to dispose of both of Foltest's bastards and become king. His claims might have even been viewed as legitimate, since he was related to Foltest in some convoluted way. The nuances escape me, though one thing is sure - he was a very distant relative.
In recounting the baron's sins, one should add that he was also the one who had ordered Aryan La Valette tortured. He wanted the youth to confess in writing that Boussy and Anais had been born of incestuous relations between Aryan and his mother Louisa. At that point the baron's plans had been different - to become king based on his personal merits alone.
Kimbolt had also had Louisa La Valette tortured. He wished her to confess that she had been sleeping with her own son, and that both Boussy and Anais had been born of the incest. Obviously, there was no truth to this.
If Geralt accuses Kimbolt:
Fortunately, through Geralt's efforts, John Natalis had Baron Kimbolt arrested. The nobleman then answered for his part in Boussy's disappearance.
If Geralt accuses Maravel:
Kimbolt was who he was, and he had done what he had done. Yet Geralt decided his investigation of Boussy's disappearance had not yielded enough evidence to accuse the baron. In John Natalis' eyes, the nobleman would remain innocent.
If Geralt accuses both Kimbolt and Maravel:
Through Geralt's efforts, both Baron Kimbolt and Count Maravel would answer for their iniquitous intentions and their parts in Boussy's disappearance. However, John Natalis lacked the manpower in Loc Muinne to deal with them both. Thus, Kimbolt's hide was saved for the time being, while the forces he commanded eagerly assisted in Count Maravel's arrest.
The Witcher 2: Assassin of Kings
The Witcher 3: Wild Hunt