Sylveon falling to C+: I dont think it's needed, it still has great typing, good Sdef, hit's behind sub, and gets a free life orb.
Mew rising to A-: it's versitile as hell, It could certainly handle the promotion.
Mega Charizard Y rising to A+: Yes, this needs to happen, it's a great mon, and is just as good as the other mega's in A+
Azelf rising to B-: Meh, it taunt's, rocks, slings out a fire-blast, or boom's, it's pretty easy to work around, but it gets the job done. could go either way.
Celebi rising to C+: counters some good shit,dies to the rest, it is fine for a raise.
Cresselia rising to C+: a big piece of meat, usually just gets hammered without doing much back, Keep it C-rank.
Conkeldurr falling to B-: It still often pulls it's weight, hit's hard and is a pain in the dick to kill, keep it B-Rank.
BRB, tired as fuck, might edit this shit later.