At first, the Zenan Bridge is destroyed, but it is repaired by the time you return from the End of Time. Speak to the knights there, then get their rations from Guardia Castle. Upon your return, agree to help them. I wouldn't recommend bringing Robo, since you'll need magic here and his Laser Spin is not very effective. You'll fight a number of battles against undead and Ozzie. You can defeat the Deceased with magic, but having everyone attack Ozzie will cause the battle to end just as easily.