Alrighty, I saw a question earlier pertaining as to why those that believe Victini should be banned should explain their reasoning, so I guess I'll do so. Be warned, that since I'm currently not getting along with this forums' BBCode, that I wasn't able to use hide tags to shorten this post up. It's long, but in my opinion, worth the read.
At first glance, Victini looks rather mundane, with base 100 Stats across the board. We've all seen these before, and to be honest, its stats aren't great. But very rarely will a Pokemon's stats push them for a ban or keep them from being banned. If that was the case, I'm almost certain that Pokemon like Darmanitan and Chandelure would have been gone ages ago. At the same time, something like Escavalier would have never dropped to RU. So lets please get off any counter-arguments that Victini's rather bland statpool is enough to warrant its stay in UU. Typing is another argument I've seen, with Stealth Rock, Pursuit, Aqua Jet, and Sucker Punch seemingly being the common arguments for Victini being UU-eligible. Using the 1850 stats and saving Stealth Rock for a later argument, I decided to go out and pull out these Pokemon, and test the odds of them actually beating Victini 1-on-1.
The first Pokemon in the 1850 stats that's capable of using Sucker Punch is Hitmontop. And it's ranked at #17 with 12.4% (33352 Hitmontop) usage. Of those Hitmontop on the ladder, only 54.3% (which means about 18110 Hitmontop) of which use Sucker Punch. However, Hitmontop cannot afford to switch-in on any Victini variant. For the benefit of those that argue against making predictions, I'll give you all the benefit of the doubt and just spam Fire-type moves, which isn't that hard to do in this tier. Here's some calculations:
-1 252 Atk Choice Band Victini V-create vs. 252 HP / 252+ Def Hitmontop: 183-216 (60.19 - 71.05%) -- guaranteed 2HKO after Stealth Rock
252 SpA Life Orb Victini Blue Flare vs. 252 HP / 0 SpD Hitmontop: 212-251 (69.73 - 82.56%) -- guaranteed 2HKO after Stealth Rock
So basically, the Physical and Special sets do so much damage to Hitmontop, that it either has to come in on the revenge-kill, meaning you've just lost something important to your team, or it cannot afford to take any previous damage. Since it's not that common for Victini to be on Spikestacking teams, Hitmontop just simply cannot switch-in, especially if for some reason, there happens to be full hazards up, since it's put into OHKO range by both sets. After all is said and done, this is the return that Hitmontop gets if it manages to come in, survive, and get off a Sucker Punch:
0 Atk Hitmontop Sucker Punch vs. 0 HP / 0 Def Victini: 112-132 (32.84 - 38.7%) -- 9.38% chance to 2HKO after Stealth Rock
0 Atk Hitmontop Sucker Punch vs. -1 0 HP / 0 Def Victini: 166-196 (48.68 - 57.47%) -- guaranteed 2HKO after Stealth Rock (if switching-in on a V-create)
So, what you get is something that can only hope to 2HKO if it doesn't switch in on a V-create, and is only managing a shoddy 2HKO if it does. I guess we can call that Sucker Punch user debunked. So Hitmontop cannot use Sucker Punch to beat Victini. Moving on!
The next Pokemon on the ladder capable of using Sucker Punch is Honchkrow, at #33 in usage. Honchkrow gets a 6.84% usage (meaning there's about 22893 Honchkrow), shares the same Stealth Rock weakness, and unlike Hitmontop, who could I guess tank a non-predicted hit from a weakened Victini, cannot afford to switch-in on anything bar a Choiced Psychic-type move. I won't bother calculating it, as we all know that Honchkrow's Sucker Punch will OHKO Victini. No surprise there. However, I want to point out that Honchkrow CANNOT switch in. Something must faint first. The odds of a choice-locked Victini switching out of a Honchkrow are pretty good too. But I noticed about 25.1% (about 5746 Honckrow) of all Honchkrow run Pursuit. Interesting, so I might as well calculate this.
252+ Atk Life Orb Honchkrow Pursuit vs. 0 HP / 0 Def Victini: 182-218 (53.37 - 63.92%) -- guaranteed 2HKO after Stealth Rock
Alright, so that means if Victini switches out, it's done. Not bad. However, you're looking at something (Pursuit Honchkrow) that sees about 1.72% usage on the ladder, similar usage to something like Walrein. Not what I'd call a reliable check, since it cannot for the life of it switch in. It's a better check than Hitmontop, since it actually threatens Victini with Sucker Punch, and on the odd occasion, even trap it, but that can be a prediction all on its own. Next!
The next Sucker Punch user is pushing into RU territory. Bisharp, ranked at a staggering #56 on the 1850 stats, sees about 3.03% usage (14811 Bisharp). Much like Honchkrow, Bisharp is guaranteed to be seen running Sucker Punch, and can and will OHKO Victini with it. However, Bisharp faces the same problem Honchkrow does, that being it cannot switch-in to anything bar a Choice-locked Zen Headbutt or Psychic. Even though it's fully capable of beating Victini, it cannot trap it nor take a hit from it (again, just spamming Fire-type attacks for those that cannot deal with prediction arguments), so I wouldn't list it as even a reliable check due to it being so uncommon and Victini being able to safely switch-out on it. At this point, we're fully enveloped into RU territory, as Houndoom, the next user, sees itself ranked at #67. It gets 1.87% usage, slightly more than Pursuit Honchkrow. Thanks to its ability Flash Fire however, Houndoom is a more reliable check, and probably the most reliable at this stage in the discussion, to any opposing Victini variant. Houndoom even gets Pursuit, which is run about 36.6% of the time. Despite being able to almost safely switch-in on Victini and threaten with either Sucker Punch or Pursuit, any of Victini's coverage moves will be doing some heavy damage to Houndoom, Bolt Strike and Brick Break being the main culprits. Anything beyond this point is probably irrelevant to discussion, as the next Sucker Punch user available, Spiritomb, only sees 0.598% of usage in the tier. The odds of running into one of those are so small that it's not even worth discussing.
In Underused, there's two Pokemon that viably use Aqua Jet, those being Azumarill and Feraligatr. Yes, both can switch-in on either V-create or Blue Flare. Yes, both immediately threaten and OHKO with Aqua Jet. However, both of them get destroyed by a Bolt Strike, making switching in a little more dangerous than both Azumarill and Feraligatr would prefer. Another downside to these Pokemon is their usage. Azumarill is ranked #50 in the 1850 stats, seeing 4.07% usage. Feraligatr is in an even worse ranking, sitting at #109 and 0.437% usage. Even though these Pokemon can beat Victini 1-on-1, the odds of encountering them are significantly small, especially those of the latter, and neither Azumarill nor Feraligatr are capable of trapping Victini, leaving it free to switch out as it pleases. Because of the above arguments, I wouldn't list them as counters, but solid checks, much like Houndoom. There's only a few aspects that they have to worry about, but are still capable of beating Victini. Not too shabby.
I touched on this briefly with both Honchkrow and Houndoom, only saving a few others for this section of the discussion. Heracross does have access to Pursuit believe it or not. However, very few people take advantage of this, and opt to instead run other moves. Pursuit, along with the likes of other moves, combine in the Ubuntu Pastebin for Heracross' moves in a section called "Other", which gets about 17.5% usage on all Heracross. If I had to guess, as I'm expecting moves like Reversal, Endure, and Rock Slide in there as well, I'd target Pursuit at about 1.7%, since the move itself does have use, and Scarf Heracross uses it perfectly, but probably won't see as much use as the Endure+Reversal sets do. Heracross is a polar opposite to the likes of Houndoom, Azumarill, and Feraligatr however, as Heracross really cannot afford to switch-in on Victini at all, and in fact, never should. This means that once again, you're losing a Pokemon in order to bring this thing out. Krookodile is the other "big" name in Pursuit-trapping. Krookodile, a Pokemon sitting at #57 on the 1850 stats, seeing 2.93% usage, carries Pursuit about 34.2% of the time. Much like Pursuit Honchkrow, the odds of running into it are not very high. Much like many Pokemon listed as an example, Krookodile can switch-in on certain moves, but cannot take a Fire-, Bug-, Fighitng- or Grass-type attack from Victini. As I've mentioned before, Krookodile has to come in on the revenge-kill in order to come in safely. Something must faint, you must be put down a man. After that, you're free to trap and OHKO. Escavalier is another name I'll point out, as it takes on the TR Variants of Victini very well, and only fears Fire-type attacks. Unlike Krookodile or Heracross however, Escavalier is exceptionally slow, and cannot even come in on the revenge-kill sometimes, as non-Choice variants of Victini obliterate it. Pursuit is one of those moves that just isn't reliable enough in UU to break Victini with. Not enough quality Pokemon run it, and Victini tends to outspeed the users, and in the extreme case of Escavalier, even after a V-create. Not something I'd consider to be a huge threat to Victini considering its awkward distribution.
I'd like to take this time to mention that the only reason I was using usage statistics is to show the threat level a Victini would experience of running into one of these Pokemon, and most of which, weren't very high. You cannot argue that a Pokemon that only sees >5% usage to be a solid check to Victini. If something has that low of usage, it's for a reason, usually because that Pokemon isn't that great. Remmeber, Victini is never a one-Pokemon team. It has partners, and the users aren't usually dumb enough to play super-liberally with Victini if they see said Pokemon.
With those parts of the arguments on "what beats Victini" out of the way, I'd like to focus my attention to those screaming bloody murder at Stealth Rock. These are textbook morons, if nothing but players who know very little about the way this tier works. Yes, Stealth Rock gets very decent distribution in this tier, yes the Pokemon with access to Rapid Spin suck, and yes the spinblockers in this tier are exceptionally good at doing their job. However, it is not impossible to keep Stealth Rock from being set in the first place. Pokemon like Crobat, Cinccino, Tornadus, and Sableye, just to name four, are all adept at keeping Stealth Rock off the field and in most cases, can beat all users of Stealth Rock. However, in the off chance that Stealth Rock is laid, it doesn't beat Victini, but is simply a deterrent. Ace Emerald and I were at one point using a team that had two Flying-types, Crobat and Tornadus, and because of the lack of a decent spinner, opted against using one. I managed 100 battles with said team, and never found hazards to be an issue, as once the late-game boils around, Pokemon like Tornadus and Victini are too strong to stop, even if they're at 75 or 50% HP. It's not hard to lead of a match against an opponent and just beat the shit out of their hazard layer. Someone touched on this earlier, but Rhyperior has two quadruple weaknesses. If I didn't know any better, I'd say leading with a Grass- or Water-type during a match when Rhyperior is on the opposing team is a bloody intelligent thing to do. Sad part is, most people leave their Rhyperior in expecting you to use it to set up on. At the end of the day, the point I'm making here is that Stealth Rock doesn't beat or break Victini. It's only a deterrent, and one that if it has to, can deal with. Look at some of the previous suspects banned from UU. Kyurem and Staraptor were both weak to Stealth Rock, and thanks to their formidable power and only slight need for team support, still managed to get nerfed. I believe that Victini is in this same boat, as the lack of safe switch-ins, the need to lose a Pokemon in order to bring out a viable check, and the hell it can raise with some team support makes it too good for the tier.
Victini is a Pokemon with very few safe checks, and almost no counters. It has access to one of the strongest moves in the game, and has one of the best movepools in regards to coverage. Its base stats, albeit not phenomenal make it a very difficult Pokemon to deal with towards the latter stages of a match. I also believe that despite the effect not being entirely severe, that Victini does cause some bottlenecking in regards to teambuilding, as teams without a Victini check are more than likely ran through with ease. Unlike Kingdra, Raikou, or Heracross, who can all be dealt with via some form of improvisation in a time of need, Victini is a very punishing Pokemon that will destroy teams not prepared for it. Also unlike the aforementioned top-tier threats, checking Victini usually requires smart prediction or sacrificing a Pokemon in order to bring a check out, and in some cases, elements of both. Part of what makes Victini a very dangerous, and potentially even a broken threat, is that like Kingdra, is that figuring out what set Victini is running can be very difficult to do, and once you know, it can be too late.
All that said and done, I'm still considering "Do Not Ban" as a valid option, as I know that there are many players who want to see it stay and they too raise good arguments as to why. I'm still open to debate on this, as I know that one, the reasons I gave for banning it aren't the only reasons it should go, two, there are a fair amount of Pokemon capable of revenge-killing Victini after a V-create or after one of their teammates have fainted, and three, there are worse Pokemon in the tier, such as Chandelure and Kingdra, that should have been looked at a bit more closely during their times of suspect.
