Be a good Kalkiite!
It sounds like you are NOT trying to use the Roth character as a base. So you are golden. There are millions of Michaels, Stevens (in all variations) and even hundreds of Roths, Rothmans, and Rothschilds. You have nothing to worry about.
But even if you were influenced by the original Roth, you still could - by transforming the way the character is seen, you are making a commentary on the character. Hamlet can be a hero or villain, depending on your point of view.
I haven't read any of the Dark Elements books, but I'm guessing the author had some concept of what they thought was right and wrong for their character to be doing. Right and wrong can, however, vary greatly based on your point of view.
In my sci fi story, I have a historical figure named Karl Kalki, who was obsessed with redeeming the reputation of his ancestor, Adolf Hitler (very Boys from Brazil). In the process, he conquers the world and introduces a brutal caste system. Oops.
His followers, know as Kalkiites, became obsessed with perfecting his work, re-branding and reinventing evil from history and giving it a new reputation. So you name your child after terrible villains and teach them to be kind and gentle, giving and compassionate. Saint Stalin is born! It's fun color to have great characters with really awful names.
It is ALWAYS possible to reinvent things. Good can become evil, heroes become villains. And that is in reality (look at how historical figures once idolized are repainted now as villains. Maybe one day Martin Luther King will be cast as an oppressor - Who knows? We can't control the future, and people can rewrite the past. Read the Chung Kou series).
So even if you find yourself straying into fuzzy territory, you just need to be sure you aren't copying, but commenting on the character and choices of the other Roth. A liberal hero can be a conservative villain, and vice versa. Most people are actually something murky and in-between, like Karl Kalki, who's heart was in the right place even if his actions failed miserably.