So far from what I'm seeing, most of you are debating on the currently picked pokemon that may need to be patched. In my case, I'm analyzing possible rescales for the following pokemon.
A. Mega Phione - looking at its improved stats, I find that the 80 / 125 / 125 defensive stats is just about as equal as a pokemon with 100 / 100 / 100 defensive stats. It may have a slightly boosted attacks that could make it a bulky attacker, but those boosts don't do much unless you're like Skill link Cinccino (Mega or Not Mega). The fact it has base 60 speed just screams trick room, it is kinda ok for there are things that could outslow her. Otherwise, fast taunt users just shut down the support variants. But if a balance is required I personally suggest giving a certain speed tier that's both too fast for trick room, but also too slow for non-trick room teams (80s-90s?).
B. Mega Celebi - whoever planned those stats for Celebi's would have been the same if I was building my own Mega Jirachi for this pet mod tier. But let's head back to business. Since most of the judges see that her new ability gives her a nasty plot boost, the way I could see she could be balanced is probably dropping her base Sp. Attack to 90. Hence, the remaining 30 (the 20+ boost, and -10 from her base sp. atk. stat) can be transferred somewhere else.
C. Mega Victini - Oh Victini. As much as I want to cosplay your mega in DOTA 2 next to Dragon Knight, I sense a bit of over smoking from your stats. Since you have both power and strength on this metagame, the way I could say hecould be balanced is actually fixing your defensive stats. Your buffs to your speed and attack are needed. But your defenses need a bit of tweaking. My proposal is actually making him defensively better in one stat compared to the other. It could either be in defense or special defense. Something like this:
Set A: If victini tanks physical hits better (inspired from Dragon Knight's stats in DOTA 2)
HP: 100
Attack: 125
Defense: 140
Sp. Attack: 125
Sp. Defense: 80
Speed: 130
Set A: If victini tanks special hits better (inspired by Lina's stats in DOTA 2)
HP: 100
Attack: 125
Defense: 80
Sp. Attack: 125
Sp. Defense: 140
Speed: 130
------------------------------------------------------------------------------------------------------------------------
Since I missed the updated editing for Cinccino's (Some Mega Mantine beat me to it. But respects for him, I like his idea), I felt like I haven't informed the rest of you on what clapyourhands (the person/admin with the animated litwick logo) told me about the balance committee's decision on how to balance the infamous Mega Cinccino that I submitted and won during the first thread of the Mega For All. I asked clap's opinion on my alternatives for my previous winning entry with these choices.
A. Keep the stat boosts, remove Extremespeed, and keep her typing Pure Normal (not Normal/Fighting)
B. Keep the added moves and Typing, but change the stats to either:
==>B1 (Stat boosts for a mixed attacker like Mega Absol)
HP: 75
Attack: 90 (+30) = 120
Defense: 60
Sp. Attack: 65 (+45) = 110
Sp. Defense: 60
Speed: 115 (+25) = 140
==>B2 (give a bit more bulk instead of spamming her best stats)
HP: 75
Attack: 90 (+30) = 120
Defense: 60 (+25) = 85
Sp. Attack: 65
Sp. Defense: 60 (+25) = 85
Speed: 115 (+20) = 135
In the end, he/she informed me in a message on his choice by this quote:
I know that I'm too late to fix the changes for her. But I kinda wanted to post this if the admins haven't heard of my proposal on balancing my past problematic entry since it's kinda my fault for not telling this sooner on the thread.
Re: Mega Celebi, I honestly don't see anything too terrifying about it. Grass is a relatively bad offensive type, resisted by Flying, Poison, Fire, Dragon, Steel, and Bug. This forces Celebi to often rely on her (comparatively much weaker) coverage. Otherwise, Celebi mostly benefits from being able to set up with her 100/120/120 bulk. After a Nasty Plot she's a force to be reckoned with, but is still weak to several varieties of common priority. Dark and Flying are especially important weaknesses, giving her a vulnerability to Sucker Punch, and to Talonflame's Brave Bird. But seriously, let's list the weaknesses: Dark, Fire, Flying, Ghost, Ice, Poison, and quad-weakness to Bug. The Grassy Terrain recovery she gets does make it easier for her to set up, however. She's 2HKO'd by coverage moves of those types from almost any offensive Pokémon, although taking Knock Off at only 130 power makes it ineffective against her, generally being a 3HKO or worse. Despite her speed she's weak to U-turn cores as she takes Bug with a 4x weakness.
For Celebi, the best fix might actually be to weaken her defensive stats to make her easier to wear down despite Grassy Terrain-boosted Giga Drain. Another might be to decrease her Speed a little and put that into offences, making her easier to revenge kill. 100/125/120/125/120/110 maybe?
Mega Victini gets no Band, Life Orb, or Scarf, and is still stuck with a bad Ability. 130 base Speed makes up for the lack of Scarf, but the inability to run Life Orb or Band is a significant decrease in power. To match the power of Jolly Life Orb Victini, it requires Adamant base 127, which isn't too big of a difference except that 130 isn't quite enough to always let you run Adamant. And Life Orb Victini generally isn't run because it still does not hit hard enough to wallbreak. For comparison, 252 Attack Jolly Mega Charizard X hits an effective 477 Attack with its STABs thanks to Tough Claws. Mega Metagross is even more powerful, and doesn't need to use non-boosted coverage moves. It's true that Mega Victini's V-create hits harder than Mega Charizard X's Tough Claws Flare Blitz, but its Def/Sp. Def/Speed decreases are very painful for Victini.
For Mega Victini, I'd recommend a stat spread somewhat more like:
100/135/105/135/100/125
Loses relevant Speed to make running Adamant less desirable, and has slightly less bulk especially on the Special side. The increase in Attack/Sp. Atk helps Victini's damage output keep up. If you're giving Victini Calm Mind, it might be advisable to swap the defences so its physical Defence is its weakest stat, as it won't be able to patch that up.
Edit: According to the Abilities spreadsheet,
the new ability Swordsman does not boost Sacred Sword nor Razor Shell. Mega Samurott would really appreciate it if this was changed, especially since Samurott gets Sacred Sword and not Secret Sword, and its Attack is its better offensive stat.
Edit2: What does the ability Fairy Mist do? It's not listed on the Abilities spreadsheet.
Edit3: Nevermind found it. It sets Misty Terrain for 5 turns on switch-in. Whoever runs this thread should add it to the spreadsheet though.