The "desire for revenge" and the "horrors of humanity" are themes that interact with each other as they show that the human being's capacity to judge and reject is what drives the wave of revenge that the creature establishes.
We can arrive at this answer because:
The creature had an open heart for humanity and wanted company and friendship, to live in a society like any other person.
But after being coldly rejected by his creator and the De Lacey family without having done anythingbad, he realized how cruel, terrible, judgmental, and unfair humanity is.
This perception, along with the negative feelings he felt, made the creature want revenge, as he needed to make humans pay for the suffering he went through unjustly.
In this case, these two themes can be considered the main elements, which guide the entire plot, in addition to interacting with each other.
This question is about "Frankenstein" and you can have more information about it at the link:
