Are you saying that Shadow Tag has been unbanned? Because if this is following OU bans then STag should be banned by default.
Sorry, I meant what Chopin said. Edited post to clarify.
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re Shuckle: At the moment, Shuckle (in the HP slot) is being presented as a Pokémon for stall teams. However, it is weak to rocks, lacks reliable recovery and has no offensive presence (ie is easily worn down and loses horribly to Taunt). It also (and this is possibly the biggest problem) competes with Mega Sableye massively - Sableye provides Magic Bounce and has an excellent typing and movepool for stall, and has very good bulk on teams such as Lugia/Giratina/Arceus. Shuckle
does wall Swellow fairly well (252 SpA Choice Specs Swellow (180 SpA) Hidden Power Rock vs. 248 HP / 252+ SpD Shuckle (150 HP) 98-116 (19.4 - 23%) -- possible 6HKO after Leftovers recovery, and no-one uses HP Rock), but I don't personally think this warrants it a slot over MSab, generally speaking.
On offensive teams, Shuckle has some utility as a suicide lead with Webs+SR, but in that case I don't think the argument of "it walls everything plsban" holds quite as well (it might prefer to go in the Speed slot, and faces competition from Deo forms and Smeargle in any case). I'd like to see more on this before coming to any sort of decision.
Shuckle in the attack slot is irrelevant to this discussion because it's nothing other that a meme, you're better off with TTar or something.
tl;dr I'm pretty opposed to suspecting Shuckle as things currently stand.
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One other thing which I just realised: I'm not sure how this is handled in the code, but currently, the Ubers slot
should be exempt from BP Clause. The only Pokémon this affects are Mega Mawile and (Mega) Blaziken, both of which offer poor stats to their team (given that you receive the base form's stats). My question is,
should Ubers be forced to follow OU's BP Clause? It's not consistent with our handling of STag, but I'm inclined to go through with this because I don't want to deal with quickpass.
edit: also PM me if you want to join the soon-to-be-established™ council