Welp, I'm going all in, bias style. Nominating Rayquaza for B+. Ya, I said it. I feel that Rayquaza is not unviable or "just another threat", and I still think it is very usable and threatening in the right hands. Yes, Fairy-types and the perma-weather nerf did hurt Rayquaza's biggest niches, but it can still hold its own with its sheer power. It is very difficult to wall if you do not scout out the set it runs, and Scarf users have declined to a select few, making Rayquaza's sweeping or wallbreaking endeavors easier. SD sets can practically smash any physical wall out there that is not resistant to Fire with V-create, Mixed sets can lure out bulky Ground-types and bulky support Arceus formes and smack them with a Draco Meteor, and Dragon Dance is very difficult to stop late-game if its checks are removed (I know that could be said for any sweeper, but this is important to Rayquaza in particular). It is usually very unpredictable at times, and access to Extremespeed is very useful for Rayquaza in revenge killing in the fact that anything that is not immediately OHKOd by a boosted V-create will be KOd the next turn by it, and it can avoid being revenge killed by opposing priority moves provided said priority user is weakened.
However, as biased as I am about Rayquaza, its flaws show more now this generation. Fairy-types prevent Rayquaza from spamming Outrage, and though this isn't too important in particular since Rayquaza has V-create, but pretty much all of them can OHKO Ray with SE attacks (that's pretty sad) due to Rayquaza's frailty and baaaaad defensive typing. Also, Rayquaza can no longer troll the living hell out of weather teams with Air Lock, but Air Lock isn't completely useless, as Rayquaza can still do sweet things like revenge kill Swift Swim and Sand Rush users, annihilate Steel-types in Rain with a Fire-type attack, and can survive a Choice Specs Water Spout from Kyogre:
252+ SpA Choice Specs Kyogre Water Spout (150 BP) vs. 0 HP / 4 SpD Rayquaza: 243-287 (69.2 - 81.7%) -- guaranteed 2HKO (Its still severely damaged but w/e)
Still, I really do think Rayquaza should get more attention than it does nowbecause Ekiller is the stupidest fucking thing ever and it should burn in hell, and despite the setbacks Rayquaza has had to endure this gen, B+ seems like an appropriate rank to put Ray in.
However, as biased as I am about Rayquaza, its flaws show more now this generation. Fairy-types prevent Rayquaza from spamming Outrage, and though this isn't too important in particular since Rayquaza has V-create, but pretty much all of them can OHKO Ray with SE attacks (that's pretty sad) due to Rayquaza's frailty and baaaaad defensive typing. Also, Rayquaza can no longer troll the living hell out of weather teams with Air Lock, but Air Lock isn't completely useless, as Rayquaza can still do sweet things like revenge kill Swift Swim and Sand Rush users, annihilate Steel-types in Rain with a Fire-type attack, and can survive a Choice Specs Water Spout from Kyogre:
252+ SpA Choice Specs Kyogre Water Spout (150 BP) vs. 0 HP / 4 SpD Rayquaza: 243-287 (69.2 - 81.7%) -- guaranteed 2HKO (Its still severely damaged but w/e)
Still, I really do think Rayquaza should get more attention than it does now