[Fyermind]

The huge trend I am seeing is very long games. With so many bulky pokemon in the tier, and lots of recovery options and resistances/immunities, games can easily drag on over 70 turns.

There is also a massive threat for quick sweeps/hole breaking because of move sets like the following:

Lugia: @white herb
Trait: Simple
EVs: 252 HP / - 252 Atk / + 252 Def / 252 SAtk / 252 SDef / 252 Spd
- Baton pass
- substitute
- shell smash
- Stored Power

Which can start firing off 260 base power stored power shots at +3 SpA form behind subs and pass off to a bouncer if it suspects whirlwind / heartswap.

There are several other powerful set-up sweepers with similarly narrow counters, so the metagame requires a large and versatile team to survive.

This leads to an increased emphasis on breaking small holes in teams. With a two pokemon defeated there is a good chance that a team now lacks a counter to one or more sweeping potentials or lacks the potential to sweep in return.

Perhaps due to a decrease in the use of magic bounce in the metagame (I'm not sure why, perhaps a surge in mold breaker deoxys-s) spore-phasing is a very effective technique I have noticed. After bouncers are eliminated spore-phasing also gathers massive momentum. For people who haven't been the recipients of this technique, it functions two basic principles:
1) sleeping counters reset on phasing
2) damage builds up over dragon tail/ entry hazards

Whirlwind circumvents substitute while dragontail avoids magic bounce, making the moves complimentary rather than reduntant. It should be noted that spamming dragontail on a mostly sleeping team makes it impossible to switch in a counter intentionally, reducing the chance of getting a counter out before losing a pokemon to as low as 1 - (4/5)^(#turns it takes to defeat one pokemon). These odds can be particularly severe because of how common dragon types are as well as the massive damage stealth rocks do to some pokemon.

Since building any momentum is a massive boon in the metagame, being able to sleep a few pokemon and scramble the opposing team can be enough to make that first break.

A few spore phasers I've seen are as follows:

Giratina @ lum berry/leftovers
Trait: prankster
EVs: 252 HP / 252 Atk / + 252 Def / - 252 SAtk / 252 SDef / 252 Spd
- Spore
- Stealth rocks
- Dragon Tail
- Whirlwind

Deoxys-s @ lum berry
Trait: Mold breaker
EVs: 252 HP / 252 Atk / 252 Def / - 252 SAtk / 252 SDef / + 252 Spd
- spore
- stealth rock
- dragon tail / substitute / other utility move
- whirlwind

Lugia @ leftovers
Trait: Magic bounce
EVs: 252 HP / 252 Atk / + 252 Def / - 252 SAtk / 252 SDef / 252 Spd
- dragon tail
- substitute
- spore
- utility move / recovery move / entry hazard / whirlwind

They all achieve similar effects in different ways such that counters to Giratina don't necessarily counter deoxys or lugia. I wouldn't suggest running all three on the same team, but having counters to all of them is extremely important.

Of interest here is that magic coat using sturdinja will eventually phase into hazards as it is now phased by dragon-tail. Whirlwind is favored over dragontail on deoxys because it's low attack makes it hard to break substitutes and win attrition damage, but mold breaker and the high pp of whirlwind allow it to set up a powerful midgame dominance by breaking magic bounce.

There are also bulk rock types who can probably execute this method effectively under sandstorm for additional passive damage, but I haven't used or seen them yet.