This is a list to have the maximum Archaon impact turn 1 while avoiding as much counter punch as possible. The objective Is to buff Archaon to absurd levels and throw him so far up the field that the opponent wont be able to ignore him, hoping to blitz the most important target off of the board in the process.
Destiny Dice: This is the big driving force behind the list, and most other Tzeentch lists. It makes it impossible to fail in whatever you decide is important.
Fate points: You have a large amount of casts, 2 from archaon, 4 from gaunt summoners (even when summoning because then the horrors will cast that turn), 1 from the chaos sorcerer, and 1 from the horrors. This is further boosted by the extra horrors in rounds 2+ giving 8 to start moving into 10 possible before your stuff starts dying. The summons should be for objective grabbing and occasional support pieces. Screamers are top priority as they only cost 10 points and the herald on disk is a close second. If you need some more mortal wounds you can do a fateskimmer from Archaon because he should already be in the heart of the battle, and fateskimmers are legit good when they make it into the heart of the enemy army to spam mortal wounds.
Agendas: If something really needs to die you can set Archaon up 9.5 inches from something and use destiny dice to get the 9 inch agenda giving archaon +1 attack on all of his weapons. Alternatively if you have the destiny dice to auto eat a monster you can use the agenda to give Archaon the +1 save.
Fate Arcanum: 160 points of free screamers, buffed screamers, free dispels all great things. Whats really great though, is 6″ of move for flying tzeentch units before game start. This means Archaon. If you have a 4 and a 5 in your destiny dice pool you can charge any target within 29 inches and get +1 attack on all of your weapons from the agenda.
Artefacts, Command Traits & Abilities
Free screamers, buffing screamers, you can make archaon fight if he dies. Nothing too exciting outside of making your units more durable for sitting on stuff
Archaon: does everything. You have a spell to give him +1 attack, +1 to hit and +1 to wound, reroll hits and wounds, reroll saves from the sorcerer, potential +1 attack from the agenda, or +1 save from the agenda if you have the right target. Because he is a demon everyone is -1 to hit him in melee, and they reroll 6;s to hit. He is hard as hell and kills whatever he touches. If you have 2 6’s and the 9 inch charge you literally kill anything other than gotrek within 29inches of him turn 1.
Gaunt summoner: horrors are worth 200 points as they are 50 wounds. so you get a 40 point 2/2 wizard that gives the units around him a -1 to hit aura in melee. The tzeentch lores are fantastic so you have a ton of options between utility and damage. In particular Arcane Suggestion is insane and should be your key spell to get off in a given turn. Alternatively his warscroll spell is great for hoard roasting, alongside the purple sun.
Horrors: With the summoners you just have 200 wounds with decent ranged attacks (3+/4+ for the main unit) that can utilize destiny dice rolls of 1 to pop more wounds back. keep in mind the agenda for doubling unit size for objective control and you’;; have a great time while they deal with the archaon distraction.
Screamers: Grab objectives in the mid to late game, and group up on any unsuspecting wizards or monsters. 12 screamers (3+3+6) with +1 rend are legitimately scary when combined with the average 4 mortal wounds they do in the movement phase. Blisteringly fast and durable enough to get the job done for 80 points
nothing to see here
Tzeentch all the way
Magic, Endless & Realm Spells
Purple sun: we had 50 points and don’t have a lot of command abilities to use. Alternatively you can bring shackles for more control
Archaon will kill almost anything in the game that deploys even remotely aggressively and if its a monster then he will be almost impossible to remove from melee on the counter punch. -1 to hit reroll 6’s to hit him and a rerrollable 2+save on a huge wound count model is simply too much. He needs to be answered though, and you kinda want them to spend time answering him. He has a spell shield so magic isn’t as effective and you have a massive amount of unbinds with 3 of them having +1 to unbind. Tzeentch buffing is silly and you can really abuse the +6″ and guaranteed charges that tzeentch gives. Don’t be afraid to absorb the hit with the horrors either, they are incredibly durable. 6+ dpr on top of the large wound count means you can sit them on an objective and expect that any equivalent point cost unit will never move them.