How exactly did you do that?Downloaded saves ?
Nope, I simply started a new game and never loaded the bugged ones again.
After giving Tiamat's hear to Samael...I have to go past this crystal barricade...But I was unable to equip the Crossblades, even with your method. When I enter chaos mode and press - or +, I do get the crossblade in that slot, but it is again swapped by that bloody horn when I exit chaos mode.
Any fix to this? This is really disauding me as I am unable to make any progress since hours now.
This method worked for me. Sorry for reopening an old post here, but if it ever happens to another player they can find another confirmation of this solution taking care of the issue without having to start the game all over.