He's a better duelist than Malgus, is more powerful than Malgus (withstanding the explosion of the Malachor temple/Cymoon 1, exploding Lyleks, ripping apart AT-ATS, manipulating freighters, collapsing massive metal scaffolds, being implicitly more powerful than Maul), Malgus is lagging behind in telekinesis/force feats to compare to Canon Vader.