I began to make a patch for fixing bugs, but in french (because I saw some typos/mistakes in dialogs too). However it can be easily done with my program
Here is a patch
that fix the bug in the US version.
I'm not uploading it on RH yet because it would be better to draw up a plan for fixing the most bugs possible in a single patch. If you or someone else wants to draw up that plan, it would be great btw ; I'm busy deciphering the script at the moment ^^'
However, I've let Iai Strike as it is. I think the transfer of the accuracy is an error : it has 30% base accuracy (Death has 35%) and it is increased by the spirit. I also personally never saw Iai Strike more efficient than Death/Countdown/Odin/etc...
I think Thunder Slash was originally thought to be a normal magic attack (as it is for Beatrix when you fight her) but it was changed to a Demi-like spell to avoid similarities with Thunder Swords. They forgot to set the accuracy in the process (normal magic attacks don't need accuracy but Demi-like spells do).