Mary Shelley uses storms to foreshadow unfortunate events, which is a Gothic element. There is the storm before he creates the monster, and the storm right before the creature kills Elizabeth, and several other storms that show something bad is about to happen.
Mary Shelley has a theme of science going too far. We have to watch out for the applications of our creations. Victor Frankenstein destroys the woman monster (Eve) he’s creating to keep the creature company because he’s worried that the new female creature could be worse than the first creature. I think that part of this is to show that while we can invent and create amazing things, we cannot always foresee their application, which may be terrible, like the atomic bomb. Science is uncontrollable and too free to do whatever it wants because you can’t have laws against something that hasn’t yet been invented or created. There was no notion at the time of creating life from scratch, so nobody could tell Victor that this would be a bad idea with bad results.
Like in “Paradise Lost,” Victor abandons his creations instead of giving it the much needed attention and guidance required.
Another Gothic element is that Victor didn’t tell anyone about his creation until his wedding night with Elizabeth. I believe that Victor didn’t tell Elizabeth about his creature, and went ahead with his wedding even though the creature had told Victor that he’d come for him on his wedding night, because Victor wanted to kill the monster. Victor wanted to destroy his creation, and the only way he knew how to find him was to create the wedding, and use Elizabeth for bait so the creature would come. This use of Elizabeth as human bait is very dark.
At one point, the creature tells Victor that I’m your master. This fits in with a theme of evolution. The creature is what Victor created, and it is superior to him in many ways just like successors in evolution. The creature is faster, stronger, has more stamina, heightened senses, and has an uncanny ability to learn at a very rapid pace. Victor is worried that should he make a female creature, the two would mate and take over earth as the dominant species. Man giving way to the next step in evolution.