I'll try to give some insight into my rankings and finally do writeups like I said I would do 3 years ago LOL.
Jirachi #1 should be pretty self explanatory, I don't have much to add I think Johnny put it perfectly in his post above. Scarf is a bit underrated, in conjunction with hazards and sand it can be a great late game sweeper, also it's a Trick Scarf user that Tyranitar doesn't really want to switch into. Wish Tect is probably the most busted and meta warping set in the game, it can snowball pretty quickly if you're not careful and give it any momentum. Personally I think Rest Talk is pretty bad Iron Head Fire Punch as your only attacking moves is just way too passive imo and if you don't use those I would rather just use Wish Tect.
I used to hate Pursuit Tyranitar but I've really come around to it, mostly I like how it punishes Clefable early game and traps Defensive Latias, it gives you a lot more tools and flexibility when dealing with stall. Strong Water type + Pursuit Tyranitar is just very threatening for bulky structures. Works great with Fighters too of course. Can't understate Pursuits value vs offense too since you trap Rotom and Latias, sometimes even Flygon if you predict correctly. DD is good but I guess I've soured on it a bit as people seem way more prepared for it nowadays. I like DD with Spikes or with Ice Punch on Tyranitar, Taunt is good too. Taunt + Pursuit is an amazing set that I've used a lot recently. Oh also sand is great!
Staple of any defensive team and defensive teams are great. You can't really get away with not using Clefable on a lot of these bulkier structure, in part due to the mirror since the best Clefable answer is.. Clefable. Bold is pretty good but difficult to fit. Copycat is an underrated option on Clefable, Cosmic Power is annoying as hell for offense but a bit useless in the stall mirror. I like CM Flamethrower a lot when you can afford it.
Yeah I think I rate Latias a bit lower then most people but I'll try my best to justify it. I don't really use Latias on offense that often, I honestly find Specs to be pretty mediocre, it kind of lacks power imo and can be a pretty big momentum sink. Scarf is good but I prefer Scarf Rotom a lot of the time, which I'll talk about later. Defensive Latias is amazing but I often prefer the alternatives (spinner cores or milotic/quag + gliscor). So basically I end up not using Latias enough for me to justify ranking it as high as others do, its defensive profile is amazing and a necessity on a lot of teams though.
spikes.
They fulfill similar roles on offense and I see them as *almost* mandatory due to their ability to force out Jirachi at least once or twice. Both also provide rocks. Heatran > Metagross because Skarmory pressure and better Boom Targets. I think dropping Boom on Agility Metagross should be considered more often it works pretty well as a dedicated sweeper imo.
Automatic addition to like 70% of offense teams for acting as both a threat while being great defensively vs Grounds,Fires,Fighters,Metagross etc. Really underrated aspect is just how diverse its movepool is, all of Outrage,Thunder Wave,Sub,Taunt,Ice Fang,Return or even Natural Gift with Liechi are great options. I think CB is also awesome for the immediate power, makes for a great lead too. Extreme BS factor with Waterfall, especially when paired with Sub and/or Twave.
I feel like Breloom is both overrated and underrated at the same time. Personally I don't find it that amazing vs offense, Spore doesn't feel that free as a click as it used to be imo. With Lum being thrown on Gengar,Jirachi,Metagross,Tyranitar and more, vs fast teams it can be hard to get Breloom in more then once so if you clunk into a Lum mon you might be in trouble
(example of what I mean). That being said its ability to pivot into Bulky Grounds and electric moves coming from Rotom/Latias while also helping vs Tyranitar is invaluable and makes it still great. Personally I never drop Focus Punch on Breloom, I think its just way too good to pass up and being walled by Jirachi and Skarmory feels so bad. Also catching one of those Lum mons trying to pivot into Spore with Focus Punch is super great. Focus Punch also lets you rip apart stall with some well-timed predictions.
For the last like year and a half I've been saying how good both Starmie and Zapdos really are, I truly think this playstyle is the most robust in DPP and gives you the ability to outplay almost every matchup. I don't think they're the easiest to use they require well timed predictions and game planning but if you know what you're doing then its very satisfying to use. Pursuit Tyranitar is a great partner to Starmie, but not necessary. You wont always be keeping rocks off through the entirety of a game with Starmie but you don't really need to. Forcing your opponent into bad trades and resetting progress is extremely valuable and sometimes the threat of spin is enough. Also worth mentioning that Zapdos can function fine vs offense with Rocks on the field still, you still check Breloom,Gyarados,Metagross etc even after taking Rocks chip. Specs Starmie is great too, so is Zapdos. Idk I could go on but I just think they're really good and my experience using them the last year backs that up.
Probably my most used Scarfer ghost typing is so valuable in this tier and helps a lot when dealing with Starmie. Resisting steel is so good for dealing with all of Lucario,Metagross and Jirachi. Basically I think it compresses a lot of checks and roles into 1 mon. I like Modest HP Fighting Scarf to patch up DD TTar weaknesses sometimes lol. Rest Talk is great too.
Not much for me to say, its just really solid all around.
I think many would say Hippowdon makes stall what it is and its hard for me to disagree. Great mixed wall, can beat Infernape,Heatran,Mixgon and more while also not being Pursuit weak. Sets sand and rocks, yea Hippowdon deserves to be ranked super high imo.
Superman teams are really good and difficult to beat, largely in part due to Bronzong. I feel like I'm the only one who likes Trick Room still but I really do think its good. It does clunk a bit into stall but the defensive utility it offers is great for offensive teams (steel + ground immunity is amazing). it enables some unique structures that can cover the stall matchup for you while Bronzong owns offense.
Great vs offense, I feel it can always at least go 1 for 1 and sometimes even more vs slower teams. Stall matchup isn't great for offcune but also not horrible with some smart play and building. Lum Cune innovation at lead is pretty cool. I like Sub with Max Spatk to mess with Clefable,Jirachi and Latias while still maintaining power. Really appreciates healing wish support.
Gengar is pretty polarizing but I think I rank it fairly, its great overall for obvious reasons just Focus Blast and Wisp are really annoying to rely on. Fast suicide Taunt is great for giving your mons setup opportunities late game. Maybe Destiny Bond should be used more. Lum is a recent trend but I think it kinda stinks since you die to sand, passive recovery from Black Sludge is too good to pass up imo.
It's similar to Heatran and Metagross I feel but it lacks Boom, though matches up better into Hippowdon which is very valuable. Empoleon + CB Tar is a great lead combo imo. AoA Empoleon with Rocker in the back is pretty good, though I think Specs is just alright, I prefer its other sets often. I also like Spdef Empoleon and Agility, SD is pretty bad I feel like but the surprise factor is good and it does fit on some teams.
Great defensive utility and can set rocks, Tankpert is super annoying for offense while offpert can be pretty good vs stall. I don't like Mixed all that much but with the right support it can be really annoying, I think it wants Healing Wish and some way of crippling defensive Latias.
I feel like Machamp is one of the most consistently threating mons on DPP, along with Jirachi and Gyarados. It's just good like every game and is so so threatening. I like the Bulk Up sets but Sub is also pretty broken. With more Bronzong > Jirachi being used on stall I think Machamp is in a very good place.
Extreme Speed and Inner Focus are very valuable for a lot of offense teams. I haven't really figured out the best way to use Defensive DD sets but I feel like they're alright.
CB is underrated I feel, Mixed is ok, Scarf is really annoying for offense and with Roost filler on more balanced teams it can be good vs stall too since you 1v1 Clefable. Being immune to basically all residual damage is pretty nuts.
Magnezone > Magneton because of its diversity and superior bulk, Magnezone is actually a dragon and electric resist while Magneton doesn't really feel like one a lot of the time. Magnezone is also better into Jirachi ofc. But I do like that Magneton opens up some unique structures and can be pretty good vs physical offense.
It's speed tier is really good for dealing with Jirachi and Suicune. Kind of competes with Breloom for me.
Both of these feel like awkward Pokemon to build around for me, since they're steel types that aren't that good vs Jirachi or Latias. I would say their main value for me often comes from their priority moves in Extreme Speed and Bullet punch. Though if you're using Extreme Speed on Lucario you're not as good vs stall since you don't have both Crunch and Ice Punch like the Agility set does. Kind of funny but I've had decent experiences using CM Lucario. Scarf is ok still but kind of competes with Jirachi and Magneton now I feel. I like SD Occa Bug Bite Scizor a lot, CB is just alright for me, not that great at trapping Latias I feel.
My god I probably have so many discord lines saying how good and underrated Celebi is, and it seems my propaganda spreading has caught on. It's physdef bulk is pretty nuts, so it matches up better in Swampert,Tyranitar,Gyarados,Dragonite,Metagross,Jirachi and Breloom compared to Latias. Seriously some of the calcs are insane, like it can eat a +1 Crunch from DD TTar so you aren't even setup bait for it. It's amazing vs offense while also having great utility vs defense. Using rocks on it can free you up in the builder but it has so many great options. Natural Cure is huge too, letting you trade with Jirachi more freely and pivot into Wisp or incoming TWaves. I really could go on forever, maybe I'll make a full post dedicated to it in the future.
Seeing Donphan pickup in usage the last year has been super cool, great mon. Movepool is amazing.
I feel like Roserade has become underrated. Toxic Spikes are still pretty good, specifically for dealing with Tyranitar and Hippowdon. Dual Spikes sets are pretty mediocre for me, I think you really want one of Stun Spore or Sleep Powder to get full value out of Roserade.
Lowkey a better Specs user then Latias. I like DD for its matchup into OffCune.
They're good at what they do, which is annoy the hell out of offense teams. Milotic is better into mixed attackers while Quagsire is better into Tyranitar.
Super bulky so its annoying for offense with Twave, great long term win condition vs stall. Should probably use it with a Cleric or with Magnezone then make Togekiss the cleric.
Feel pretty fringe but are ok at times.
My god I love Abomasnow I think its so good and underrated, honestly I kind of want to move it higher. It's surprisingly really damn hard to switch into and can annoy the hell out of offense with Leech Seed or just claim victims with its Mixed set which feels so difficult to switch into. Also it can threaten stall since it's actually threatening to defense cores. I don't think its as hard to build around as some people say it is, it can fit on a fair amount of teams and the payoff is well worth it. Yeah, great mon I will always be an Abomasnow advocate.
It's so damn bulky and hard to force out due to sticky hold. Has a lot of great sets like Curse,Counter or personally I've liked Modest Yawn a lot, it's kind of unexpectedly tough to switch into and is good vs stall.
They're kind of similar mons and I feel they're both underrated. If either get behind a Sub it can snowball out of control very fast. CB Rhyperior kind of just claims one every time it comes in. I think its a myth that Rhyperior needs sand tbh, it functions fine without and your opponent will set it a lot of the time anyway. Rhyperior > Mamoswine because its superior bulk I guess and I feel it needs less support. Both abuse paralysis very well too.
Camerupt feels too slow and dies to too many attacks but it also really wants leftovers so you can't even tech a Passho on it or something, blegh. It's ok from time to time maybe but it got overhyped.
Not bad in theory but in practice it doesn't feel that good for me and it's super difficult to fit since you lose the Water and Fire resist that Latias has.
I have faith that Slowbro is pretty good, it checks too much broken stuff to not be (Machamp,Jirachi,Gyarados,Metagross). But.. I haven't really found the right fit for it yet.
Registeel is really cool tbh, great bulk and access to Twave,Seismic Toss,Rocks and Explosion so it kind of just has to be good. I have a few teams with it and they've performed pretty well. Super annoying mon.
Steelix Ground/Steel typing is cool role compression, I think its viable somewhere.