Dwimmerstrath, the Bowge of the Sorcerors
In Malebolge, there is a deep ravine patrolled by powerful baatezu. This is the Bowge of the Sorcerors, known as Dwimmerstrath. Within are imprisoned the petitioner-spirits of evil wizards, who write spells for the baatezu. Perhaps only one spell in every thousand researched here meets the exacting standards of the baatezu noble Shemihazah, who oversees the project, but that's still enough to upset the Tanar'ri. As a note, all the petitioners here appear to have had their heads turned around through 180 degrees, so that they face backwards. The reason for this is unknown, but it's probably part of a research project of some kind. Amongst the spells discovered with help from the hapless petitioners here were tanar'ri tribulation and undetectable lie. Acidic blast may also have been one of theirs, and they're certainly part of the team working out an antidote for or suitable reply to chaos hammer.
In Dis there is another of the baatezu's twisted petitioner research projects. Those who, in life, perverted their religions, are kept in concrete tombs with only a writing-desk for company. They pen venomous tracts for the baatezu, who distribute them to the more wavering members of the faiths of good to promote doubt. However, the heretics themselves gain no satisfaction from their work, as the baatezu memorize or copy the tracts out of sight of their authors, and then burn the manuscripts dramatically, further souring the already bitter minds of their artists. They never understand what's going on, and become more and more convinced of the uselessness of existence....a view they are careful to place in all their tracts. Recent works from these wretched souls include A Considered Dismissal of Sapientism, The Folly of Freedom, and the especially poisonous What Your Faith Wants From You, in which prominent religious figures in Sigil are portrayed as crooks and robbers. The petitioners don't actually know the names of these people: the baatezu simply plug in the latest names to keep up to date.
In Avernus, not far from the tranquil realm of Garden, there stands in the barren desert a huge free-standing archway, perhaps 70 feet tall or more. Carved upon it are the faces of baatezu, on the one side, and slaadi on the other. If you view it, or enter it, from the side marked with slaadi, nothing happens. But looking through the other side reveals the swirling chaos of the plane of Limbo. Aside from the occasional use of 'Limbo' to denote Avernus instead, what possible reason could there be for such a chaotic intrusion into the smooth running of the deadly baatezu political engine? There's always a reason. Many years ago, a high-ranked baatezu noble devised a plan to poach territory from other planes, especially the prime, that involved using chaos-stuff as a pathway. The plan was duly enacted, and several pieces of land stolen. It's said that Garden was such a place. But after a while, the scheme proved unprofitable compared to dragging gate-towns off the Outlands, and the site was transferred for other uses. There is no way to shut the gate, and anyone entering it is likely to be hurled headlong into Limbo, although there's a small (15%) chance they'll be sent to some Prime world instead. Guarding the gate are the new inhabitants of the plot: the monsters known locally as Sin and Death. Sin, the mother of Death, is a demigoddess like a night hag, although unrelated to Cegilune, Baba Iaga and the other hag-goddesses. Some say she's the younger sister of Malagard, others that she's the Dark Lord's own daughter, like Glasya. She's invincible as long as she stays near the gate, and can draw on its power to twist the minds of those she speaks to. Death is almost always silent, just watching. He's not the true Death that the Dustmen worship, but a minor Baatoran demipower. He's still no joke to fight, though, because he can kill anyone who possesses a scrap of doubt.
