The smallest and furthest major moon of Dobuna, the Red Death of Rhosai is named after the dwarf titan Rhos. A barren volcanic world with an aura of red death, the moon is a scorched wasteland. Rhosai is toxic, Rhosai is dangerous, Rhosai is volcanic, but Rhosai has mines. It holds many mines from first era days, populated still by the dwarves who were left behind. The most important resource mined here is Arkaan, the meteoric black metal used in a lot of ancient Omniborn creations.

Despite its heat, some icy craters are found on the surface of Rhosai that are forever unable to melt. By its very nature as the furthest moon of Dobuna, being on the surface of Rhosai at the right time of year, month, and day would allow you to be the closest you can be to the sun.