Age of Sigmar/Tactics/Edition 1.1/Daemons of Tzeentch
War Scrolls
The common key words of these warscrolls are: CHAOS, DAEMON, and TZEENTCH.
Heroes
Lord of Change: Has a lovely command ability if you've got lots of of Tzeentch Daemon wizards and is an actually very powerful caster by himself, since you need to roll fucking awfully to screw up casting rolls with him. On the other hand, he's kind of fragile and his melee potential is absolutely awful for a 10 Wound monster.
Herald of Tzeentch: Has a pretty cool combination of tricks going for him. He has a unique spell with a casting value of 9, which is pretty fucking high. Also, once per game, he can cast with 3 dice instead of two, making 9 much more reachable. Also, if he casts with a value of 9 or more (no matter which spell) he can cast another one. Basically once per game you can cast twice unless you roll real bad. Keep in mind that casting with three dice, adding Chaos Familiars and a Lord of Change can mean that once per game you can summon anything including the way overpowered Soul Grinder.
Herald of Tzeentch on Disc: Oddly the disc is disturbingly powerful in melee. However, the Herald on it wants absolutely nothing to do with melee. Ultimately, the Herald on Disc is a confused beast, best left alone.
Herald of Tzeentch on Burning Chariot: When deciding how to build the model, do consider that this unit doesn't get the magical flames shooting attack that other heralds get, or the blue horrors close combat attacks that the exalted flamer gets. In other words, if you build this version, you can use the Blue Horrors to increase your Pink Horror units, the Exalted Flamer by himself and all the flame bits for nice conversions.
Kairos Fateweaver: A good hero choice if you already have another that you are using for their command ability (because he doesn't have one). Old Fateweaver can can get any dice roll to anything you want once per game. Casts 2 spells per turn and changes the lowest dice roll to match the highest one. He will likely get off any spell you are shooting for. Gift of Change does an incredible amount of mortal wounds so aim for that being one if you are within range; it also automatically makes a Chaos Sp-thing with even one dead model: if you retreat with the thing that turn instead of attacking, you guarantee the unit will have to kill it next turn, slowing them down so you can shoot them again next turn. Truly, a brutal spell. Kairos has no shooting, but he's not bad in CC.
The Changeling: A fun little hero unit. Can deploy on you opponent's side of the board and can't be targeted by anything until he is revealed by another hero coming within 3" of him or you personally using an ability. Until then he can half the movement on a single unit within 9" every turn. Good on certain occasions like when your enemy brings a few fast units to keep you from moving up the board or getting close to artillery. Bring for fun not for game breaking madness.
The Blue Scribes: Now a very powerful caster. They can automatically cast anything on 2+ with 1 D6 and to unbind their attempt, you need a 9 or more. This allows you to cast any overpowered summoning spell with umpunity. Don't want to be a jerk? No problem, their signature spell makes it easier for other Tzeentch Wizards to cast.
Troops
Pink Horrors: One of the best infantry units in the game. Not only do they shoot pretty well and on a surprisingly high range, each unit also counts as a Wizard, so they can either shoot some Mortal Wounds at stuff their normal attacks can't get through, increase their save to 4+ or summon some more bullshit.
Blue Horrors (Silver Tower): Some saint at GW decided to bless us with a warscroll for Blue Horrors in the Silver Tower game, apparently having forgotten the utter lunacy that once ensued because of them. Basically, a Blue Horror is a Pink Horror, but worse in melee, slightly lower-ranged shots and no magic. But that's really not the important part. The important part is that, so long as you have the warscroll and the models, you can set up 2 Blue Horrors whenever a Pink Horror is killed, thus adding two more wounds your opponent has to chew through before he can get at the actually important stuff behind them.
Brimstone Horrors: And because Pink Horrors splitting into two blue wasn't insane enough, killing a Blue Horror creates a (paired) Brimstone Horror, which are basically teeny-tiny swarms that have only 1 Wound despite clearly being 2 distinct lifeforms. These are even weaker than the Blue Horrors but provide yet another bunch of Wounds your opponent has to chew through. If we ignore the scarcity of the Brimstone Horror models, under perfect conditions, it would take 50 Wounds of damage for your opponent to chew through 10 Pink Horrors.
Exalted Flamer: Has twice the wounds and twice the attacks of a normal flamer, and that's basically it. I'd just take two normal flamers and put this chap on the chariot for the extra stuff that can do. But if you plucked a Chariot apart or built it with the Herald on top, fielding this guy really doesn't hurt, as absolutely nothing in the game enjoys being pelted with 6 damage D3 shots from 18" away.
Flamers: Pretty bloody great. They die very easily, so keep them in cover, but their ranged flame attack is possibly the best thing Tzeentch daemons can bring you, massed shots (10 from 3 of them) causing D3 wounds on anything that gets through is awesome. Bonus flaming is nice too - remember "healing" in AoS only affects models that are still alive, if flaming one-wound stuff it doesn't mean models get up again if you roll a one afterward. In summary using a wound-based comp system (or no comp system) you'd be a fool not to bring at least three of these. Also, remember the awful Locus of Transmogrification? It's been buffed to hell and back and given to these guys. If they lose models while close to a Herald of Tzeentch/Blue Scribes/The Changeling, they have a chance of the Flamer simply splitting into two new and fully healed Flamers. And all the ones that don't split, you simply summon back to the table with your buttload of casting attempts. Lastly, they have 9" Move and can fly (by jumping, according to their warscroll!), so you can use them as ultra-powered horse archers, leaping here and there while puking multi-colored death from a safe distance.
Screamer: A bit pillow-fisted overall. Three of them won't do much, they want to be in bigger units to achieve anything (even lone wizards might not die quickly to them otherwise) and you're unlikely to put plenty of wounds on units, though monsters really don't enjoy the damage upgrade to D3. Do remember you can do the slashing fins attack if you "retreat" from a combat they're not going to win by flying over the unit they were fighting.
Exalted Flamer on Burning Chariot: Ridiculous, utterly ridiculous. Has the potential of inflicting 46 Wounds per round, if you do it just right. It can damage units it flies over, has the same powerful missile weapon as the standard Exalted Flamer and a bunch of melee attacks, including the two Screamers, who make 6 attacks, each of which deals D3 damage whilst targetting a Monster. None of these have Rend, but whatever. Take a couple and dominate the game. However, these things are pretty fragile, not that this means anything when you have a goddamn 14" Flying Move stat.
Formations
Daemon cohort of Tzeentch: Could be fairly nasty if you play fair. If not, it's utter rape. Extra spells means you could reliably be casting Arcane Bolt and Mystic Shield with every unit (including your Horrors) every turn. Having most of your army with +1 saves while throwing multiple sets of D3 mortal wounds across the field, plus normal shooting, could be nasty. You'll probably want to borrow some speedbumps from somewhere to keep enemy units at arm's length. Lord of Change probably best for his command ability giving a bonus to cast. And all of this is not taking into account the fact that you could use summoning magic with all your casting attempts.
Changehost of Tzeentch: A Lord of Change takes 9+ units between every Tzeentch Daemon unit that is not another Lord of Change. In each hero phase two units within 27" from the Lord of Change can teleport in each other's place. You can do it twice if the formation includes 9+ units, and three times if there are 18+ units. This can be fairly nasty, but you need to use it correctly. For example, plonk a unit of hard-to-kill Horrors in front of the unit that was just busy cutting your Flamers apart. Or bait a monster into attacking your Horrors, then switch them out for Screamers with their bonus against monsters. There are lots of possibilities, but you need to think these situations out beforehand, as it's a huge-ass Battalion and it's only worth its cost of entry if you know how to make use of it.