The invaders fought back; Malcom encountered Malgus, witnessing him killing Republic Special Forces soldiers. The soldier fired several rockets towards the Sith Lord with his rocket launcher. One rocket hit Malgus and engulfed his body in a large and blinding explosion.

Is Malgus dead?

Darth malgus doesn’t die. He becomes cryogenicly frozen and taken to the grand master emperor as a trophy. Which means even in the present in the star wars story line Darth malgus is alive but frozen and he could wake up anytime whatsoever from his cryo state.

Is Darth Vader more powerful than Malgus?

Vader was 80% as powerful of the most powerful Sith of all time. Malgus, though incredibly powerful, was not in the top ten most powerful Sith. There would be a serious fight but Vader wins 7/10 times. Vader was definitely the strongest of the Clone Wars era, where he was insane in overall power and skill.