Hi! How are you? In my story, I have powers that are separated into certain elements (air, lightning, earth, plant, water, ice, fire, light, and dark are the categories). However, while I was planning out a minor villain with the power to control mercury, a friend pointed out to me that the villain shouldn’t be able to control mercury in both its liquid and solid forms if water and ice are two different categories. Should I combine water and ice into just water? Or leave it? I really want to leave it, so how can I make this work? Thanks!
Looking at the elements you have as categories, I do see a few inconsistencies that could make them feel contrived.
While the ice vs water one is an issue, I can think of a fairly simple fix for that. You have light and dark, so fire and ice might actually represent heat and cold. That would mean ice elementalists shouldn’t be conjuring frozen water out of thin air, but they could freeze whatever’s around.
The bigger issue is that some of your categories are very general, and some are quite specific. Mercury is one element on the periodic table, whereas earth generally represents all of the elements found in nature in a solid state. You have three different types of energy: fire/heat, light, and electricity, but all gasses fall under the broad category of air.
The more specific you get, the more people will ask “what about x?” and the more elements you need. If mercury is an option, why not carbon or silicon? If you have plant elementalists, what about animal elementalists? Fungi elementalists? (Fungi elementalists would be pretty cool.)
If you’re having trouble coming up with a natural-feeling set of categories that allow you to have your cool mercury villain and eat him too, you could change the way your magic system is presented to make irregularity feel natural. Instead of presenting a specific number of categories, you could say that the elemental control everyone has comes in endless varieties. Some people have broad control, some people have control over very specific things, some elements are more common for people to have than others, and rare or unheard of elements inevitably pop up from time to time.
If you do that, you’ll want to consider power balance. If some people control earth and some just mercury, are the earth elementalists superpowerful in comparison to mercury elementalists? Or do people get better control if their element is more specific, thereby balancing out the power levels somewhat?
Since I don’t know the details of the story, I can’t say what the best solution is for you. However, you have an option other than getting rid of the elements you like.