Quick Smogon Forum grammar lesson for y'all (for funsies, explaining what charlie said, and knowledge!):*Who's
it's = it is
its = (it has ownership of -> ["its move, Thunderbolt"])
whose = subject's ownership ["Pikachu, whose house is worth $2,000"]
who's = who is ["Who's that?"]
Terastilization/Tera is a noun, so "tera" is inaccurate.
would've = would have ["I would've gotten away with it if it weren't for you meddling kids!"]
"It" is a gender neutral pronoun, which is correct for most Pokémon without a set gender (inaccurate use of that word, but I think the accurate one may be banned on the forum). Blaziken, for instance, is not guaranteed male or female; so "It" or "They" is correct, unless it is a specific one. As well as this, a lot of legendaries cannot be male or female, so it's also the only canonically accurate choice there.
Council being capitalized or not depends on context. If I say "The Smogon Council", that is the name of a group of people, and therefore still correct. However, if you say "The Council" and it's not a set group of people, I think it's supposed to be lowercase. Correct me if wrong!