He killed Proteus for literally no reason other than crazed jealousy and to make Frank suffer. It was ridiculous.
He's just poorly developed in my eyes.
They want him to go both ways as the scary menace and the tragic martyr.
Problem is, both are rushed and therefore annoying and boring to look at.
He kills his brother and says it was mercy to kill him, as that was no life... then he wants a hot companion to bang and is willing to kill a living person to have one.
He contemplates suicide for being a creep and assaulting the actress, but it's like he totally forgot how he snapped the neck of a poor man who had done nothing to him, just to send a message and prove a point.
His terrible actions aren't the climax to a build up of tension, and that's why they don't register as the actions of a troubled individual, but those of a random bad guy, yet in the middle you get all of his moping and monologues about how cruel humans are, even though 70% of them have been overly kind to the guy
And to justify all of this, you'd have to actually show him suffer some major shit.
This was a time where very few people were having a comfortable life, you were born with mental illness, look at what Vanessa got through, you weren't white? You were a poor woman? you were deformed? You were gay? And so and so on.
People lived in absolute shit conditions by default, unless you were a well off white magnate or some shit (and even then you weren't really shielded from the poor understanding of medicine).
So to show him get pushed around once by a couple of drunks, and be called a "monster" once by an obviously asshole actor, doesn't really sell the struggle, especially when the same show juxtaposes it with the back story of Vanessa, or even just Chandler and Malcolm, who have clearly seen and done some major scarring shit in their "expeditions".
Even Dr. Frankenstein is shown to have a more tragic back story, with his mom vomiting blood on him (comically just after mourning the death of their dog) or Brona, having to suck dicks for a living just to not get married to an abusive and violent husband, and dying puking blood in the process.
To me, they just didn't sell the monster AT ALL, and that's why every time he's on screen i wish i could fast forward, and it's doubly annoying when a character like Van Helsing gets killed to further his shitty plot.