"Hellish" is often a word used to describe the world of Koiogra IV and is indeed the one most widely used by those who have braved this toxic planet. The portions of the planet which are not covered in lava flows are just as inhospitable to exploration, with the constantly heaving surface being blasted by hot, abrasive winds between bouts of stone-melting acid rain. Some scientists have theorized that the atmosphere of  Koiogra IV semi-regularly comes in contact with that of nearby Koiogra III, with which the smaller planet shares a close orbit. The two worlds share similar volatile gas ratios in their atmospheres, but beyond this little is known, as data is hard to collect from such a hostile world.