Desperate to escape Leman Russ, Magnus used his powers to transport his Legion to the Eye of Terror on what became known as the Planet of the Sorcerers!
Let’s dive into how this planet, newly occupied by Magnus and his Legion, became known as the Planet of the Sorcerers.
Via our good friends at Lexicanum
At the conclusion of the Battle of Prospero, Magnus the Red used his sorcerous powers for a last-ditch master spell, transporting the surviving warriors of his Legion through the warp to another planet, one promised to them as sanctuary. This planet is now the Daemon World of Magnus the Red; dark, rocky, volcanic and in constant turmoil. Its skies are storms of warp energy; low-hanging multi-coloured clouds cover the land and rain drops of energy to fill up the unnaturally dark rivers and seas. The Sorcerer’s Towers of the Thousand Sons thrust up from rocks jutting from lava plains, twisted mockeries of what the City of Light once was.
Dwarfing all other towers is Magnus’s own, an obsidian monolith called the Tower of the Cyclops. As well as being staffed by thousands of servants and troops, Magnus’s tower also possesses a sorcerous, great, glowing eye. The Eye of the Tower watches over the planet, its gaze also penetrating through the warp into the material galaxy. This allows Magnus to sense the arcane artefacts and gifted psykers which fascinate him, so that he can despatch his Thousand Sons to raid the Imperium.
When the Thousand Sons first arrived on the planet, they found it unpopulated. Over thousands of years of raiding, they have acquired a multitude of minions. This has created a servant underclass, some of which have escaped their masters into the hostile land.
These escaped servants then often join the nominally independent nomadic warbands upon the Planet of the Sorcerers, warbands led by both Champions from the Thousand Sons or powerful mortals risen from the ranks of the escaped servants. Often, these mortal champions arising among the warbands are then recruited back to serve the Thousand Sons.
Individuals with psychic powers are much sought after for the Thousand Sons to act as servants, becoming known as Thrall Wizards, psykers bound to the service of particular Sorcerers. Also notable is the amount of Beastmen arisen upon the planet, a subordinate population group that developed over thousands of years. While some of these mutants – specifically referred to as Tzaangors – enter various warbands, most remain wild. Little is said of flora or fauna, apart from the presence of Chaos Hounds amongst some warbands.