Mothmen are a Servant race that was created when Koss was chiseling the cool white flame of UN. Their race was in the forefront of helping around his workshop, and "tending" to the flame. The tending being worshipping, and they rarely got much else done.
Mothmen, as most Servants, are immortal and don't die of old age, but still killable. When first created they replicated fast. When they became more of a nuisance than help, Koss cast them out of his workshop and flung them onto Throne's moon.
They lived life peacefully until the Universal War. After the Universal War and the disappearance of Throne's moon their numbers started dwindling and now they are scarcely to be seen anywhere in the great Wheel.
Though most think that Throne's moon got destroyed during the Universal War, Jaagup was one of the few religious followers who set it to a different course. The moon got damaged and pieces of it got strewn out into Throne's orbit, but much of the moon still remains in disrepair.
Many mothmen died during the Universal War defending their homeland in the sky. But at the final moments of the moon, a religious group, of which Jaagup was a part of, decided to hide the moon in plain sight to be healed. A task that none of them were prepared to know and face the length of. Jaagup being now the only one remaining for this arduous task.
Hiding the moon is a continuous psychic task. The shield of cover will only remain up if it's maintained purposefully. This is also a reason why Jaagup doesn't have access to his full mental powers, as he has to uphold a constant link to protect his homeland. If that link would be to break, it would not only break his will, but bring forth all of his capabilities in full force.
The mothmen believed that Throne's moon is alive. They then, acting as a nurse and caretaker, to bring it back to life. Furthermore, the religious followers of the moon have formed a link with the moon, hearing her cries of anguish.
After the Universal War Jaagup didn't find a place in Throne between the manipulation and maliciousness that the guilds had been sowing, and for years drifted in the Wheel. But with purpose: to find ways to heal the moon.
For years now he is settled in Rayuba, working in an observatory as an astronomer, in turn being allowed to do his own research. Collecting information of times gone by, and how to revive their beloved moon to full health.
He carries the moon with him in plain sight. When you see a dark spot in the sky at night, that's where the moon is hiding.
Jaagup can scarcely remember the time before his current quest. He is now only focused on bringing back the moon, as it is believed to bring their race to enlightenment once more.
He carries with him his trusty rope darts that he acquired in days gone by. They're imbued with the ghosts of servants who help him around the observatory and otherwise. Often lazy or shy to come out for work.