Everytime Seth makes an action, he gets a +2 speed boost, but I don’t know how he gets it or how can I disable that.
Any ideas?
And I noticed this bug after I applied the class expansion patch, and it only happens with Seth, the other units aren’t affected.
But I think it pretty cool 
Didn’t you have a similar problem like this a while back?
I’d suggest making sure all character pointers for Seth are filled out properly. I had a problem a while back where I had forgotten to give a character a support pointer, and as a result they gained a +5 res bonus when they supported.
The support pointer doesn’t seem to be the problem, and looking closely, the problem is caused after the unit (Seth) enters in the battle for the first time in the chapter, after that the bonus is obtained after every action.
It seems that the problem is in the stat check process… ?
I don’t know.
I’d suggest applying the class expansion patch on a vanilla rom, and see if things still mess up. Hopefully it’s a problem with the patch and not your rom. Worst comes to worst, and you don’t have a backup, you can just use another character slot.
I finished the test in a vanilla ROM, and the problem doesn’t happen. Now I have no clue of what is happening.
Maybe someone can figure it out when I release a demo.