After playing some matches in the ladder, i could see that a lot of people improved many ways how to use Victini, maybe even betten that it was during XY UU.

Mixed sets became a lot more common during this suspect ladder, so actually it’s common to worry with the possibility of dealing with Mixed sets, along Choiced sets, making it even harder harder to scout / switch-in reliably. But ORAS UU introduced / popularizated (even more) a lot of mons which can pressure Victini, like Salamence, Aerodactyl, Mega Swampert, along with Bulky-waters like Swampert and Suicune, but it isn't close to my reason. I see a lot of interesting of arguments saying that Victini had almost zero hard counters because of flexible moveset, but for me, even though Victini never had theorically any hard counters, the combination of specific Pokémon in various teambuildings can be pretty useful to cover it. For example, some Balanced teams, can combine the use of a use of a Bulky water-type + Dragon-type to cover the majority of Victini’s sets, considering that Water-types switch-in more comfortably in Choiced sets, and stuff like Hydreigon, even hating U-Turn, can scout incoming moves for Bulky-waters, even if it sounds strange in practice actually. Offensive teams can explore even more options, thanks to its dynamic nature, allowing Victini tends to cause problems usually only with Scarfed sets, which some mons can pick the momentum from it (like Pursuit trapping, or making a set-up move on a locked V-Create -1 in his both defenses).

But the main point of view of it, is the V-Create Spam. Even with the drawbacks mentioned above, V-Create is the reason what makes Victini so threatening, and it forces a lot of risky situations for the opponent just because of it, because when you see Victini in a 1v1 scenario, even with scouts you need to think twice before making a move, because he can BREAK stuff or regain momentum too! For example, a scenario where Victini sees a Bulky-water like Suicune or Swampert in a Team Preview, he can just Trick or U-Turn (or attack right away with mixed sets obv., which are simiarly applied to his common Fire-resists, like Salamence, Arcanine, etc), and team support is even more impressive here. VoltTurn cores, Toxic Spikes support to name a few. Even with Victini not beating EVERYTHING clicking V-Create, he does have almost a zero opportunity cost, especially against Balanced or Bulky Offensive teams.

For that reasons, i think that Victini is too good for the tier, and it should be banned from UU.