Ilsensine
The Great Brain. LE greater power of mental domination, magic (It/Its)
Pantheon: Illithid
Symbol: Glowing brain with two tentacles
Realm: Outlands / Ringlands / Caverns of Thought
Known Proxies: All illithids (if you believe the chant)
Put on that metal helmet cutter, and let me whisper you the dark of Ilsensine, the mind behind the mind flayers and a real piece of work even by the Outlands‘ standards. Picture a great, green-glowing brain, tentacles sprawling out like the dark of a bad dream, reaching into the corners of the multiverse. This ain’t a normal kind of power by any stretch of the imagination; it’s a deity of thought, a master of knowledge so cold and calculating it’d freeze the blood in your veins.
Ilsensine’s got itself a realm of horrors deep under the Outlands, in the twisty, turny tunnels known as the Caverns of Thought. This place, it’s a mind-bender, a soul-twister. Get too close to the centre, where the Big Brain itself sits brooding in a pool of cerebral fluid, and you’ll start feeling the heavy weight of thoughts not your own. It’s like having your brainpan scrubbed with steel wool, only the scrubbing’s all psychic-like and less enjoyable.
This god-brain’s not one for company, except maybe for those with a hankering for brain-melting secrets and psionics powers. But here’s the catch: Ilsensine’s game is all about its own power. Not the kind you wield with a sword or a spell, but the raw, uncut stuff of the mind.
Now, the dwarves of Moradin’s Anvil nearby, they give Ilsensine’s digs a wide berth. Can’t blame ’em, not with those mind-controlled zombies sauntering out of the dark, eyes empty as a tax collector’s heart. These spies of Ilsensine, they’re out there, scooping up secrets and serving them up to their brainy overlord.
Ilsensine’s philosophy? Rule everything, enslave everyone. Simple, right cutter? But it’s the way it goes about it—through psychic domination, subjugation, a total psionic lockdown. It wants its illithid children on top, with all the rest of us “cattle” down below in the save pits, ready and ‘willing’ for the taking. And if you think you can shield your noodle from its noodling, think again. Venture too deep into its realm, and you’ll be lucky to leave with your wits about you.
So, what’s Ilsensine doing in the Outlands, a place of balance and all that? Some say it’s because of the brainwaves, the constant thrum of thought that pervades the plane. Others reckon it’s got something to do with Gzemnid, another power with a penchant for tunnels and dark dealings. Or perhaps it’s because of the River Styx. The truth? It’s anybody’s guess.
But here’s the dark of it: Ilsensine’s realm, it’s a place of knowledge, yes, but also of horror, of minds bent and broken under the weight of an intellect so vast, so alien, it could only ever see us as things to be used. You want to know more? Be my guest, but don’t say I didn’t warn you.
Canonical Sources:
- Dead Gods [2e] p17,19 (brief mentions)
- Dragon Magazine #342 p75 (brain slave of Ilsensine spell)
- On Hallowed Ground [2e] p76,81,83,87,91,136,176
- Planes of Chaos: Book of Chaos [2e] p23 (Ilsensine banished the Mad God)
- Planescape Monstrous Compendium Vol. 2 [2e] p26-27 (eater of knowledge monster)
- Player’s Primer to the Outlands [2e] p29 (brief mention of realm)
- Planescape Campaign Setting: Sigil & Beyond [2e] p15-17,26,32-33,38-39 (realm description, other brief mentions), ; Monstrous Supplement [2e] p9 (cranium rats as servants of Ilsensine)
- Sigil & Beyond [5e] (brief description of realm)
Uncaged: Faces of Sigil [2e] p29,106,123
Source: Jon Winter-Holt
