Generally in Godot, when you get an error it will cause an avalanche of errors afterwards as the engine will attempt to keep going as long as it can. This is most likely the case here and the first error is the cause. It says that you put the spell's function inside the dictionary. In the last paragraph of this post https://itch.io/post/1182794, I described this problem and the solution. But basically you need to move the "func" part of the code you added to the file to an empty space near the bottom of the file. You'll find a bunch of other spell "func" down there.
There could be other problems due to adding the spell to "spelllist", but I won't know what they are till this is fixed. If there are then a screenshot of the spell file for the lines with the error would help. The second line of an error lists the file path and line number of the problem.