So there’s plenty of posts about Darth Vader trying to look cool and dramatic through out many different comics and shows. To be honest, I think I can come of with an explanation for this (other than he’s one of the most iconic characters ever and they wanna show him off).
When re-watching the finale of Season 2 of Star Wars Rebels I for some reason took big notice of Vader’s line after Ezra said he’s not afraid.
“You’ll die braver than most” (or something like that, my memory isn’t the best)
Now it’s established even as Anakin he had incredible abilities with the force and with a lightsaber, and while those are definitely important, anything else that would help him hunt down nearly every last Jedi in existence would help. His abilities in combat can’t be discounted to this end, but I think we should look to a character that is also known to have killed many Jedi but unlike Vader had no ability with the Force.
Grievous is introduced as an incredibly terrifying force in the original Clone Wars show and in various comics, having defeated and killed many Jedi without any information of him becoming known to the Republic. While his robotic body and lightsaber abilities definitely make him far from helpless against most opponents, his inability to use the Force would cause him to lose in combat against Jedi in a normal duel.
Look at his original appearance in Clone Wars. He’s shown as a mysterious figure, terrifies and surrounds numerous Jedi, and when one panics and rushes out he crushes him to death in a single moment and disappears again, and then proceeds to defeat a group of Jedi and only fails to kill them due to the intervention of some Clone Troopers. He fights by making sure his enemies are scared and distraught and then picking them off or crushing them before they can come up with a rational plan. He was one of the most effective forces (ha pun) in cutting through Jedi during the Clone Wars, and both Count Dooku and Palpatine stressed his use of the unorthodox and making sure his opponents could not fight him on even ground.
(there’s even a scene in the original 2003 Clone Wars where he’s practicing with Dooku and Dooku keeps telling him that he must be prepared and to keep whatever opponents he may face off balance)
I’m sure Palpatine probably noticed the effectiveness of Grievous’ abilities and found some way to put them to use with Vader. While a good knowledge of lightsaber techniques and incredible powers in manipulating the Force could probably explain most of his abilities in wiping out the Jedi, I’m sure Vader wouldn’t mind knowing how to keep his opponents scared and incapable of even putting up a collected effort.
But hey whatever random Star Wars thoughts go watch the 2003 Clone Wars if you never have before it’s Good.