Isidro has always dreamed to be, if not a soldier, the best mercenary warrior of his time. The inspiration for his ambitions is the legend of a once formidable captain - the great "Hundred Man Slayer" - who fought in the original Band of the Hawk.  Although Guts has never revealed to Isidro that he is in fact the young boy's idol, he has supported his dream nonetheless. Being a younger member of the group, Isidro looks up to Guts as a father figure, despite his insistence to the contrary. Currently, he is training under Guts, hoping to achieve his dream of becoming the greatest swordsman in the world.