AURORUS
Role Identification: Choiced Special Wallbreaker
One thing worth mentioning is that your team is very, very light on Special Attackers. This isn't your fault, there aren't that many special attacking dinos around, but it's a weakness. Luckily for you, Aurorus has some pretty serious chops as a wallbreaker - which means someone who's very good at getting rid of stally, bulky Pokémon, but lacks certain attributes (usually Speed) to be used as a sweeper.

The idea of a special wallbreaker is to either force out the opponent or kill 'em dead with a powerful STAB move. Give your Aurorus the ability Refridgerate - which transforms Normal-type moves into Ice-type ones and gives them a 20% boost in power (and anyone making a pony reference will be SHOT) - because your other option, Snow Warning, doesn't really benefit anyone else on your team. Having Hail up would give you a perfectly accurate Blizzard but not much else, and it would also mean damaging your team slightly while the effect was on the field. You'll want to run a Modest nature to boost your Special Attack more, with the following EV spread: 252 points into Special Attack, 252 points into Speed, and your four leftover points into Special Defence.

For moves, you want Hyper Voice, Freeze-Dry, Earth Power, and Frost Breath. Hyper Voice is the strongest Normal-type special move you can use every turn, which is fairly important to stop you being revenge-killed by the next Pokémon to switch in; it benefits from Refridgerate, becoming an Ice-type move with 108 Base Power. Because it's classified as a sound move, Hyper Voice is also able to ignore Substitutes, which annoys a lot of wall and stall Pokémon to no end. Freeze-Dry is another Ice-type move, though lower power. Why do you want it? Because it's super-effective against Water-type Pokémon, which normally resist Ice, and bulky Water-types are very common walls (for example, my team runs a Toxapex, which is the dictionary definition of an evil Water-type wall). Frost Breath is another Ice-type move, but this one is special because it always incurs a Critical Hit, meaning it does 100% extra damage AND ignores defensive stat boosts. Users of moves that boost Special Defence (like Iximaz's Reuniclus, which tends to run a Calm Mind set) had better watch out. Finally, Earth Power is there as Ground-type coverage, which will hit a lot of your threats exceedingly hard - Rock-types, Fire-types, and Steel-types who might think you an easy switch-in would be on the receiving end of a very rude awakening. I'm aware there's no Rock-type moves on this list, but Rock as a typing is not known for its special attacks - the highest Base Power move Aurorus knows is Ancient Power at 60BP, and it's simply not enough.

As for the item, go with Choice Specs. They boost the user's Special Attack by 50% but lock it into one move. However, since Ice and Ground is such a brilliant offensive combination, generally you'll be okay whatever you pick.

BASTIODON
Role Identification: Utility Lead
Bastiodon... isn't great. Sure, it's got huge defensive stats, but it doesn't have reliable recovery outside of the Leftovers item and its typing gives it two 4x weaknesses to the very, very common Ground- and Fighting-types. Its offensive presence also leaves something to be desired, like existence. Oh well. Let's make this work.

First things first: give your Bastiodon the ability Sturdy. This means that, as long as it's at full HP, it cannot be killed in one hit by direct damage. Think of it as kind of like an inbuilt Focus Sash. You'll want a Careful nature to protect against special attackers - nobody with a 4x weakness to Fighting wants to be on the receiving end of a Focus Blast, and it's fairly common as a coverage move. As far as your EV spread goes, you want 252 points in HP, 4 in Defence, and 252 points in Special Defence. This means you've got more of a chance to survive what your opponent will throw at you.

As for your own moves, you want Stealth Rock, Toxic, Roar, and Magic Coat. Stealth Rock and Toxic form the core of this set, with the former setting up chip damage for enemies when they switch in and the latter being its only reliable way to cause damage to its foes. Roar is a phazing move - it forces out the opponent and drags in another, allowing you to rack up more and more damage from Stealth Rock, spread more Toxic where applicable, &c. Roar has a Priority rating of -6, meaning you're guaranteed to go last, but since Bastiodon is outstripped by passing glaciers this is not a huge concern. Finally, Magic Coat allows you to reflect status moves like Will-O-Wisp, Thunder Wave, and Taunt back onto the user. Status isn't a huge concern for Bastiodon, but it's never pleasant to deal with, and Taunt shuts this set down completely. Finally, give it Leftovers for some vital, if meagre, HP recovery.

HAXORUS
Role Identification: Physical Stallbreaker
Haxorus has a sky-high Attack stat and a very usable Speed, meaning it can maintain an offensive presence against a variety of Pokémon. The following set pairs very well with Minior, as it allows Haxorus to beat the living snot out of things that might counter Minior and let Katie B. mop up the stragglers.

First, select your shiniest, stabbiest Haxorus from the stable and give it the ability Mould Breaker. This allows you to ignore certain abilities when making your attacks. For example, let's say you're fighting a Weezing. Weezing has Levitate, which makes it immune to Ground-type moves - which you want to use against it, because Ground is super effective against Weezing. With the Mould Breaker ability, you can use a Ground-type move and hit the Weezing, something that in the competitive scene generally causes your opponent to have an enormous temper tantrum. They're always fun to watch. For the set we're running here, you want an Adamant nature to boost your Attack out of the blocks, with your EVs spread as follows: 252 Attack, 4 Special Defence, and 252 Speed.

The moves you want are Swords Dance, Dual Chop, Earthquake, and Poison Jab. Swords Dance boosts your Attack by two stages, meaning that you can then power through basically anything foolish enough to stand in front of you. Dual Chop might have a fairly low Base Power, but it hits twice and therefore deals with Substitutes, Focus Sashes and the like. Earthquake and Poison Jab are there to deal with the Steel- and Fairy-types that think they can come in on your Dragon-type attacks. A +2 Poison Jab will generally make any Fairy-type start having an extremely bad day, while +2 Earthquakes will make everything else have a bad day. Do bear in mind, though, that this set is walled by Steel/Flying-types like Iximaz's Skarmory and newbie SquidBoi's Celesteela, so you need to be willing to switch out with this set.

Finally, the item you want is a Lum Berry. This might seem a bit odd - why not a damage-boosting item like a Life Orb? Well, Haxorus doesn't like being on the receiving end of status effects like Burn, Paralysis, or Taunt. The Lum Berry lets you ignore that status effect and kick the opponent's teeth in unmolested.

MAROWAK-ALOLA
Role Identification: Utility Attacker
Ghost/Fire is an extremely difficult STAB combination to counter effectively, and Alolan Marowak has the attacking chops to use that gift effectively. This set is designed to maximise the damage you do with Ol' Boney here while still retaining survivability.

First, get an Adamant one and give it the ability Lightning Rod. This has a number of benefits. First, it makes you basically immune to both Burns and Paralysis, which would otherwise cripple a physical attacker like Marowak. Next, it gives you a free switch-in on Electric-type attacks, which is always useful. Finally... well, the other options are kind of bad. Rock Head has its charms, but I prefer not being paralysed. As for EVs, you want 252 Attack, 4 Special Defence, and 252 Speed.

Now let's get onto your moves: Shadow Bone, Fire Punch, Bonemerang, and Will-O-Wisp. Shadow Bone, Alolan Marowak's signature move, is great way of dealing reliable damage due to only Dark-types resisting it, and it also has a 20% chance to lower the target's Defence stat by 1 stage, meaning that if luck is with you you can hit a lot harder. Fire Punch is preferred over Flare Blitz because the recoil element is just too much damage on someone with no reliable recovery (unless one runs Rock Head, but then one may be Paralysed and it is a debilitating experience). This is also your big counter to Steel/Flying types that so plague the Haxorus set above. Bonemerang, which used to be a signature move, is an extremely able thing indeed; a Ground-type move with the same effective Base Power as Earthquake that can hit through Substitutes? Sign me up. Finally, Will-O-Wisp allows you to spread Burns across opposing physical attackers that might otherwise do you considerable harm.

Your item - and it should only ever be this item on a Marowak - is good old Thick Club. It doubles your Attack stat, meaning that Alolan Marowak's brilliant STAB combo now hits like a freight train. While this does make it Knock Off bait, you're able to put some serious hurt on Pokémon who don't run it - and there aren't that many who can.

KOMMO-O
Role Identification: Special Attacker
This is one of the times when I'm going to deviate from the Smogon orthodoxy - I think you can get more out of other moves in this context than you can what they prescribe, and thereby get more power out of your selection. Here goes nothing!

Select a Modest-natured Kommo-O and give it the ability Bulletproof. This is the ability that will render you immune to a wide variety of moves - a full list may be found here - which, by extension, makes you more survivable. For your EV spread, you want 252 Special Attack, 252 Speed, and 4 in Special Defence. This maximizes the benefit of your Nature and allows you to do more horrible things to people for longer. Which is always good.

For moves, you want Autotomize, Clanging Scales, Focus Blast, and Flash Cannon. Autotomize boosts your Speed by two stages, allowing you to outspeed most opposing Pokémon after a single turn, which is handy for a sweeper. Clanging Scales is your main STAB move, a reliable 110 BP special attack with the downside of lowering your Defence by 1 stage every time you use it. Focus Blast is your other STAB move, and really it's a do-or-die thing. It hits a lot of Steel-types for excellent damage, but that is predicated on it hitting at all - which, when the move has an accuracy of a mere 70%, is far from guaranteed. Flash Cannon is there to bait your foes; Dragon/Fighting has a double weakness to Fairy, and there's a temptation to throw out a Fairy-type like Iximaz's Togekiss or SquidBoi's Mimikyu to soak up your STAB moves. Flash Cannon hits them for super effective damage and can catch them severely off guard. Finally, give it a Life Orb to hold. You're looking to do more damage... so do it! Just beware that you're on the clock; Kommo-O has nothing at all in the way of HP recovery.

TYRANITAR
Role Identification: Physical Tank
Tyranitar is a brutal-looking kaiju of a Pokémon, and it shows in the design and movepool. Sandstorm benefits a large number of your team members, boosting Minior, Bastiodon, and Aurorus's Special Defences (as well as its own) to stratospheric levels. However, its role as a bludgeon requires some fine-tuning.

First of all, the ability: it is Sand Stream. Just... just use Sand Stream. Unnerve is insufficient for your purposes. It sets up the Sandstorm weather condition for 5 turns, which will allow you to put chip damage on the field for everyone who isn't a Rock-, Ground-, or Steel-type. This is useful for breaking stuff like Focus Sash, Multiscale, or Sturdy. Your giant stompy rock monster should have an Adamant Nature and the following EV spread: 4 HP, 252 Attack, and 252 Speed.

Next, we have the movepool of Stone Edge, Crunch, Earthquake, and Pursuit. STAB Stone Edge is a seriously meaty move; its accuracy isn't the greatest at 80%, but between 100 Base Power and an increased critical hit rate, it can dish out a lot of hurt when you do manage to land it. Crunch is just a good move; Dark-type STAB with 80BP and a 20% chance to lower the target's Defence, which is helpful. Earthquake's utility in combination with Stone Edge is well-storied; what one can't hit for at least neutral damage, the other generally can. Finally, we come to Pursuit, which is a very interesting move. It deals double damage when the target is switching out, allowing you to get kills you might not otherwise manage against more fragile targets. It relies upon a certain level of prediction, of reading what the opponent is likely to do... so if you want to swap it out for type coverage like Superpower, Iron Head, or Ice Punch, then I completely understand. =]

At last, the end is near. This is a Choice Band set, which is like the aforementioned Choice Specs but for the Attack stat rather than Special Attack. It allows Tyranitar to bulldoze its way through the specially defensive walls that might shut out Aurorus, paving the way for midgame wallbreakers like Kommo-O and Haxorus, as well as lategame cleaners like Katie The Death Malteser Minior. You have a reasonable team composition. Hopefully this little guide helps you use it to its full potential. =]