mh... I often heard about stealing Ragnarok from one of the gods...
perhaps there may be a chance to do a rare steal... you may get it instead of Minerva, Red Jacket or Safety Bit...
but I don't think so!

On my first runs through the game I took the Esper, but after I've saw the paladin shld teach it as well, I always took the sword, and its great
PS: bet it at the Colloseum to get the unbelievable Illumina-sword