For some reason, after the China beach scenes, I can no longer look at my spells, nor use any in combat. This occurred after I went through the end of China, which I did finish with neither Asa nor the MC alive, through the use of the summons. While dead, I also equipped a wand that I found which changed my basic attack into an ice lance. I went back to the main game, bought several new spells from the fairies (All of the green, plus Kraepellin Clones). I then wanted to try to fight in the arena using these new spells, loaded up a fight with Asa, and got this exception the moment I clicked my name when asked who to attack with. I proceeded through the fight, lost, and the problems persisted afterwards. I tried starting a new game, and it does not have this issue, leading me to believe it is a problem with the save itself, which is also why I am giving so many details about what lead up to this exception. I apologise if I have written too much, but I have no idea what can and cant be useful information in this circumstance. 
You have too many spells. Might be Alzheimer's thievery. I'm guessing it didn't restore a spell after death. You learnt a bunch of new spells, went into combat, and then the Alzheimer condition ended and your spell was brought back. Only a guess though, I'll have a look after work.
You can fix this using the renpy console. Type in: len(h.skills) - this will give you the number of spells you currently have. If it's over 8, that's your issue. Simply remove one with: h.skills.pop()
I believe this worked as a fix, but I must admit, it took a bit of effort/research to learn how to open the console to begin with; the settings had the console turned off in the config files, so it wasn't quite as easy as using the command. Could just be that I'm dumb, but it might be worth keeping in mind when giving advice like this lol
I am allowed to start combat now, but I still can't fight properly; After killing a flame spirit summoned by Asa, it stays on the field, turns blue, and is automatically targeted when I try to attack; it also has a message about not being able to find a corpse?