These particular ones are driven by the Russians discovering a mysterious new element called element 99 which can manipulate time and space as well as mutate living things into zombies, Gamera or anything in between... and can no doubt also tenderize meat, shine your shoes, and whatever else is convenient.
Nick Naylor: Cigarettes in space? Jeff Megall: It's the final frontier, Nick. Nick Naylor: But wouldn't they blow up in an all-oxygen environment? Jeff Megall: (Beat) Probably. But, you know, it's an easy fix. One line of dialogue: 'Thank God we created the, you know, whatever device.'
Limitations are more important than abilities. It applies to characters – what they cannot do, what they won’t let themselves do, is more interesting in general than what they can do. It applies to worldbuilding. The costs of living in a harsh world are more interesting, often, than the benefits.
Extrapolate: In developing your magic, your job as a writer is to look at how the changes you’ve made will affect the world as a whole. Keep this within reason, depending on your story’s goals and lengths.
Interconnect: Tying your powers together thematically, and asking yourself how they play into the themes of your novel, will very much help you worldbuild and expand, instead of adding. You’ll end up with a magic system that feels like an important part of your book, and less like it includes “everything and the kitchen sink.”
Streamline: “How can I take some already-existent piece of this world, and show a new culture’s reaction to it?”