Since it's Zunesha, I wonder if the headache Momo had following his declaration that he should not die back in 1014 was actually Zunesha trying to contact him then. It would know Momo's part in all this, and that it's linked with its eternal roaming over the seas. If Momo knows he must not die, then he knows the mission he must fulfill which may finally give Zunesha the respite it's longed for.