I'm making a small personal patch for FE8 (which I would be happy to release as an ips patch at some point if people are interested!) and one thing I want to do is make the Jump Festa event items available in the main game in some fashion, along with Alacalibur, the name of which I've already corrected to the clearly-intended Aircalibur.
This in mind, if Aircalibur is to be used, the glitch in its animation that cuts the music off should obviously be fixed. Based on my admittedly rather limited knowledge of ROM hacking, it is something that seems like it would likely be caused by something simple, like an incorrect byte or two in the command list for the spell animation, but I don't actually know what I'd need to change, or to what, in order to fix the issue.
Is it known what the source of this issue is? Have people fixed it before? Any help is much appreciated!