I pretty much agree completely with both the Professor and BuzzH. Trask was the extreme; pure evil hiding under a mask of sanctimony. That I think is what makes everyone react the way they do to him. Petofi on the other hand is a typical omnipotent villian, like Goldfinger, FuManchu or the Emperor in Star Wars. Wants complete power and domination and loves playing head games -- but always to a purpose.
Trask on the other hand, even more than Nicky Blair, is evil for the sake of enjoyment of evil. Closest equivalent I can think of offhand would be the kind of "Christian" to whom it doesn't matter about behaviour or ethics or the following of the teachings -- they feel they can behave however they want because their belief is all they need.
Personally the thing that gave me the worst case of the crawls about Gregory Trask was the implication of molestation/rape with both Rachel AND with Charity. It's hard to think that that was there by accident -- the cast and or writers HAD to have put that in deliberately. True, some implications are sort of built into the Victorian novels they swiped from, but I think they took it further.
And speaking of that implication in Victorian literature, here's a point to ponder. To give you some background, for the last couple years I have worked for a child welfare organization where, although I don't deal directly with the neglected abused and molested kids, I had to undergo some very thorough training on child abuse and the signs and signals that a kid is being molested. A good amount of the behavior we see in something like Trask with Charity or Rachel, or the complete package of the stock character of the Victorian Rake (read Quentin) are also behaviour patterns that are warning signs that the child, youth or adult was a victim of molestation or sexual abuse.
I'll tell you I was quite shocked when I realized that.