It depends. Some might think he is better in the novel as it offers more depth to his character. Others might have a different opinion based on personal preferences.
General Grievous was a feared and powerful cyborg general in the Star Wars universe. He was the leader of the droid army of the Separatists. He was known for his four lightsaber combat skills, which made him a formidable opponent. He had a very menacing appearance with his skeletal body and multiple limbs. His backstory involved being enhanced with cybernetic parts, which increased his strength and combat abilities. He was a key figure in the Clone Wars, causing much trouble for the Jedi.
I don't think there is a specific canon comic dedicated solely to explaining General Grievous. But you might find some background info in related comic series.
I'm not entirely sure as there could be various stories within it. But generally, it might focus on the character General Grievous, perhaps his origin, his battles, and his role in the Star Wars universe. It could also explore his unique abilities and his relationship with other characters through the graphic novel format.
General Grievous was a Kaleesh warlord who later became a cyborg general in the Separatist Droid Army. He was severely injured in a battle, and the Separatists rebuilt him as a cyborg. He was a fearsome warrior, known for his ability to wield multiple lightsabers and his tactical skills in combat.
Well, Obi - Wan Kenobi has shown time and again his ability to adapt to different opponents. He defeated General Grievous, a formidable foe. Pong Krell, on the other hand, was consumed by his own dark desires. When it comes to a fight between them, Obi - Wan's use of the Force for defense and offense, his lightsaber skills which are refined over years of training, and his wisdom in combat situations would make him the victor. He can sense his opponent's moves and counter them effectively, something Krell's overconfidence might not be able to handle.
Obviously, General Grievous is a main character. Since it's a story in the Star Wars context, there could be other characters like his droid minions who assist him in his battles and operations. And, depending on the plot, some Jedi knights might be important characters as well. For example, if the story is about one of his major battles against the Jedi, the Jedi who oppose him in that battle would be key characters.
One of the most important aspects is his transformation into a cyborg. It made him into a powerful and terrifying adversary. Another is his role as a leader of the Separatist droid armies, which was crucial in the Clone Wars. Also, his combat skills with multiple lightsabers are very significant as it made him a tough opponent for the Jedi.