Spoiler
so like we pretty much know for sure palpatine didn't teach Vader everything he knew because if he did Vader would have overthrown him immediately. Just imagine if Vader actually had all that training. He would be actually unstoppable
His nose wrinkled with disgust. He was not accustomed to resigning himself to being afraid.
"He brings a veil of darkness with him wherever he goes. It distorts the force around him. It's blinding. Suffocating." He gritted his teeth slightly and took his staff from his back , turning so he was halfway facing Tarkin. "He has committed atrocities I'm not even sure I can fathom." He pointed his staff towards the door. "With the flick of his wrist." He flicked his weapon in a short slicing motion, as if to decapitate the air in front of him. "No one in their right mind shouldn't fear him; Sith, Jedi, or otherwise."
Not to mention he was the guard dog of the emperor, who was on an entirely different level of mysterious and terrifying.
