https://pokepast.es/814e84fe40ae595e
This team was designed to facilitate specs hydreigon while taking advantage of SD cobalion taking care of both chansey and scizor.
We have cobalion as our stealth rock setter and swords dance sweeper, and it acts as a reliable check to scizor, being able to shrug off all 3 of its main attacks, potentially gain a justified boost by switching into a knock off, and use sciz as set up fodder and then kill it with close combat. It also is a great check to zarude, and its base 108 speed is pretty good as well.
Excadrill is here as our hazard setter and is our best check to nihilego. Excadrill is one of the best if not the best hazard remover in UU, with good offensive and defensive utility, with it's steel and ground type combination being quite useful, and packing a threatening earthquake that even pokemon with levitate can't avoid. It's also good at spreading toxic.
Raikou is here as our speed control, possessing the coveted base 115+ speed tier, and also having reliable pivoting capability thanks to volt witch. It is great at removing bulky waters and flying types, on top of being able to spread burns with scald, and threatening weakened zarudes, hydreigons, and excadrills with aura sphere.
Hydreigon is here as an incredibly powerful special wallbreaker once all of its counters are dealt with, and this team already has the tools to remove both of the water fairies in the tier, togekiss, and chansey. Without those 4 pokemon, hydreigon can tear through most of the tier with its stabs, and can fry both steels and grasses with fire blast. Sleep talk allows it to act as a check to amoongus, and destroy it with either a specs boosted draco meteor or a specs boosted fire blast. Cobalion and Hydreigon pair together quite nicely, since one is good at removing the tier's special walls, while the other is great at removing the tier's physical walls.
Slowking is here to check both mamoswine and conkeldurr, which both destroy this team. Slowking has some of the best defensive utility in the tier, can spread burns with scald, and can use teleport to bring in the more offensive pokemon this team has to offer.
Tangrowth is here to act as a check to primarina, which is the bane of hydreigon's existence, and cobalion also isn't too fond of prim, acts as an amazing counter to zydog, and can even check azu in a pinch. Assault vest is used over rocky helmet here since cobalion already has a rocky helmet and we need a more specially defensive wall.
I feel that this team works very well when all of the pokemon are put together, and is relatively beginner friendly.