Trying to think of ridiculous ways to use Endless Spells, I came up with this, as I'm dedicated to Chaos....another Grand Alliance might be able to do it better? Also I have no idea as to how things could play out with this either, but wouldn't it be fun to try!
140 Overseer's Fatetwister: Battalion
200 Herald on Burning Chariot (General/Arch Sorcerer/Staff of Change/Aura of Mutability/Treason of Tzeentch)
380 Lord of Change (Wellspring of Arcane Might/Unchecked Mutation)
140 Herald on Disc (Staff of Change/Bolt of Tzeentch)
140 Herald on Foot (Staff of Change/Arcane Transformation)
140 Blue Scribes (Tzeentch's Firestorm)
100 Exalted Flamer
480 3x single Burning Chariots (battleline with the Herald on Chariot as General)
Then for Endless Spells I have Ravenak's Jaws, Burning Head, Pendulum, Geminids, Shackles, Cogs, and Balewind. I figure after they cast a bunch of Endless Spells the Cogs and Balewind will help a couple cast extra of their normal Tzeentchy blasty spells or the like. And the whole army, as few wounds as it is, can drop at once letting me probably go first and thus cast spells without much interference and be out of unbind range. Thoughts? Anybody try this yet?