Far Realm
The Far Realm is a nightmarish plane of chaos and madness, home to unspeakable beings so terrible they are sometimes thought to have been ripped from the darkest dreams of madmen. So unfathomable is the Far Realm and its denizens that its very existence is a perversion of reality itself.
Many of the most terrifying races in Syra originated from the Far Realm, including beholders, grell, aboleths, and the infamous illithids. Known as aberrations because their very physiology defies the natural order, they delight in sowing chaos and devastation throughout the world. Some, such as the illithids, even seek to conquer it.
While small ripples or tears in the planar barriers are not uncommon, they are generally unstable and only allow in small numbers of aberrations before they close. Large, stable, and/or permanent gateways are exceedingly rare, and when they are discovered they are always closed as quickly as possible to prevent major incursions. Recently, however, the wizard Tephra opened a stable gateway in the ruins of Estorium, admitting a continuous stream of aberrant beasts. She also sent through the portal Lifecutter, the scythe of the dead god Nerull. The Brightstone Heroes are currently mobilizing an army to fight through the aberrations and close the gateway.