Darth Malgus/Veradun is clearly intended to be an Expy of Darth Vader/Anakin Skywalker. Despite existing nearly three-thousand years apart, their similarities are striking.
They both wear respirator suits? Check.
Were both forced into those suits after suffering defeat at the hands of a trained Jedi? Check.
Though it is important to note that, while Vader has to wear his mask with the respirator full-time to survive, Malgus is able to survive for a short time without it. This is shown in the novel when he temporarily removes his respirator to passionately kiss Eleena.
Both joined the dark side expand their Force powers along with the intent to rule the galaxy? Check.
Neither of them taken seriously by their colleagues? Check.
Anakin had it the hardest as he wasn't taken seriously, neither by the Jedi, nor by some of the Imperial higher ups.
Both have a woman they love who also acts as their Morality Chain? Check.
Both killed their love interests which tipped them even further towards the dark side? Check.
Again, it should be noted that while Malgus killed Eleena in order to seal his loyalty to the dark side, Anakin/Vader accidently killed Padme when his intention to turn to the dark side was to save her from death.
