Many spells (magic fist, wall of blades, etc.) simply cannot be assigned to any element :(

I think that the best option (now) would be to return to the old concept of spells...or completely rework them! As an excellent example, consider the elemental spell system from the third game. By adhering to it, spells can be adequately categorized...but not all of them, so the option I mentioned a few lines above is the best :(

However, it is possible to change the animation and names of some spells, adapting them to the desired element. For example, replace the wall of spears with a wall of stones, and the storm with a sandstorm =/

Perhaps the fire trap should still be placed in the fire element?