Belissar - Environment: Ancient records and legends indicate that Belissar's atmosphere was once fully breathable and hint that it may even have been pleasant. While that may have once been true, this is no longer the case. Toxic compounds now flood much of the planet's atmosphere, water, and surface.These represent a substantial hazard to any Humans who might visit the world. The poisons are also one of the key factors for ongoing mutations among the cultists who continue to inhabit the world.In some regions, the toxins are so dense that they hang as a thick fog over the world's surface. The massive clouds are visible even from the void. Deathwatch tracking systems indicate that some of these clouds have been in existence for nearly a solar century, occasionally migrating but never dissipating.Within the clouds, filtration systems are necessary for breathing and vision enhancement is essential for any sort of navigation. Travel through these regions represents a significant risk, even for Space Marines, and must not be undertaken lightly.At times, these toxic clouds form into complex weather patterns, often due to interactions with other nearby pollutants. The resulting storm systems can be deadly -- not only from the wind shear and blinding rain -- but also from the incredibly corrosive nature of these elements.Belissar's unstable nature makes predicting such catastrophic events nigh-impossible. The storms erupt spontaneously and sometimes dissipate just as inexplicably.Even more dangerous contaminants possess other portions of this foul planet. The taint of Chaos has warped not only the world's inhabitants but the very essence of Belissar.There are countless enclaves of the Warp-spawned remaining on this world far from the Hadex Anomaly. The majority of these locales are made up of decidedly unnatural geographic features. The very surface of the planet may act against any who dare to tread upon it.In some such places, the planet looks and acts like a living being. Ground has become flesh and massive hairs, feathers, or scales sprout from its surface in place of foliage. In a few places, the surface flows with blood and bile, creating loathsome rivers and lakes.The unholy Warp-spawn that inhabit such locations sometimes take on physical appearances that are consistent with these places -- or it might just be a manifestation of the land itself.Kill-teams that have travelled into such "living" regions report attacks by creatures that resemble massive immune cells and mouths that spontaneously form and open before attempting to devour their battle-brothers.Other regions, which first appear comparatively mundane, exhibit a more subtle Warp contamination. Such locations appear to be relatively clean of toxins and even exhibit signs of native flora. Closer examination inevitably reveals that the land itself is alive. The planet's raw materials come to life and attempt to destroy intruders.Even a sacred bolter has limited efficiency against a cliff that makes a deliberate effort to collapse upon a Space Marine. Records suggest that regions such as this are most easily identified by their lack of visible pollution, but this is hardly a reliable benchmark.