PEACH
Peach's Magic Number is 105%
Peach for Mewtwo needs to be a long match for any hope of winning. Basically, Peach is completely covered in approach, has a better projectile, and priority. Some Peach players like Forward air on your shield or spaced to stop approaches, followed with either jabs, grabs, down smash or a retreat.
Call and chase the retreats with grabs at low % and tilts at higher %, and you might be able to forward air out of shield the down smash if it didn't eat under your hard shield. If the forward air hits your shield, you're fine; Peach can't follow up because Mewtwo slides. If it pushes you to the edge, then slowly plan out how you're going to get back on the stage and avoid stupid hits. Basically try not to take unnecessary damage, as everything counts for both people in this match. Peach dies early off of the top except on DL64, and Mewtwo has to die from forward air, neutral air, forward throw and other moves at moderately higher percentages.
If you get Peach off of the stage, and she's at an altitude where you can back air, be patient and wait for a good one to throw and force an air dodge, chase a neutral air and keep chasing until you see she can neutral air you. If she's above you, chase with up air if possible, force Peach to throw her float and double jump cards and keep yourself in a position where you can make something happen.
On the stage, catch projectiles if possible, though her throws are better, if there is a lot of distance, then just back up and baby shadow ball spam hoping for an opening. If Peach wants to be a *****, then you gotta choke her like one. If you're down in percentage, then you gotta turnip/shadow ball approach get grabs/down tilt forward air combos and just slowly rack up the damage for the throw KO. Throw her off the stage and see if you can get some cheap kills with back airs and edge hogs, otherwise take it for the easy % if possible.
Most of this hasn't really changed.
"If Peach wants to be a *****, then you gotta choke her like one."
OFFENSE
You generally want to down throw at low percentages, back throw off the stage at medium percentages when applicable. You can out space her down smash with down tilts BARELY, so keep that in mind when you want to pressure her shield. Up throw KOs, Forward air when applicable. Some decent combos on poor Peach players are:
Down tilt > Forward tilt > down tilt > Forward Tilt/Air >>> If Forward air then follow for the up air.
When you have her on a platform stage and you call her float:
Back air > Up air > Back air
is a good combo as you follow her using the platform between the up airs and next back air as she tries to DI up from getting hit.
You're mostly looking to neutral air her float and techs on platforms. Shadow ball her floats to get her to aerial or bring her down on the ground again. You want to keep doing that until you find her rhythm and start calling her approaches and retreats.
Fully charged shadow balls also help create set ups when Peach is floating. They force her to get out of the way some how. You generally want to throw it so it hits under Peach's dress to force her up and have a longer way down, it also serves to just hit her because she thinks it might just go under her or she was already performing an aerial.
DEFENSE
Peach's float cancels are really difficult to match up against. Fortunately, Mewtwo has a very big shield to absorb those blows and can often run circles around Peach and just straight up run away to the ledge and stall for your shield back after her attacks.
Until you figure out her rhythm for your offense, you're looking to punish every little mistake Peach makes. Poorly spaced aerials should get tilted, grabbed, or shield grabbed. You can encourage more mistakes by doing lots of small subtle movements like facing away then doing a quick pivot shield on her attack. If she grounds herself after the attack and goes for jabs, pressure her with a disable out of shield if the jabs are long and not properly spaced.
Neutral air out of shield on floated down airs that aren't well spaced or timed. Charge your shadow ball when there is distance on the Peach. Catch poorly thrown turnips and use them for a possible approach of your own. Peach throws items faster than you do, so you have to be careful when you use it offensively or you'll get neutral aired.
Low percentage down smashes from Peach are devastating, so when you're playing a down tilt spacing game, make sure you ****ing space, lol. You're really just looking to down tilt at medium percentages during a ground game or in between aerials where she can't crouch cancel you easily.
Stitch faces are gay, catch/avoid like normal. Bomb-ombs too. If she pulls a beam sword, do your best to get it from her. If you get that sword, you know have a viable and consistent ground spacing game against her. You can play her like Marth, shut down her float game and have a quick, viable ranged projectile.
When you down throw Peach, always be ready for a retaliated neutral air dropping back down on you. You just have to watch her DI. If she DIs up/neutral/back into you, don't go for the forward air at early percentages, go for up tilt instead if you can. You generally don't want to challenge Peach's aerials unless you're underneath her, her trades are often better than yours and her priority is also just better. You're looking to just keep moving and slowly building that damage until you can choke dat ***** and up throw her.
EDGEGUARDS
Back air and Up air is pretty much all you need and have for high recoveries. Baby Shadow Ball her float if you can and Teleport edgehog/SUNC and down smash mix ups for when you force her a bit lower. Otherwise, if she just tries to land on the stage, have your down tilt/KO grab/ Forward air ready for her.
LAST THOUGHTS
She did not bake you a delicious cake. You're going to take her cake and all of her cookies, so don't bite on any of her ****. Be patient and she will have to come to you if you have a solid defense and spacing game. She is Peach though, so you will get hit when there's nothing you can do about it. Just keep trying to avoid the killing blows, reset when you need to and create/wait for your openings with solid spacing and shutting down common Peach play like above head level floats, spaced dash attacks, and turnip spam.
Questions/Comments/Concerns?
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MR. GAME & WATCH
MAGIC NUMBER IS
110%
INITIAL THOUGHTS
I don't really have much to say on him. He is a better character than Mewtwo, but he is very light and floaty like Mario. He has aerial priority, and a great SHFFL Shield pressure game. A good CC down tilt, good jab, decent wavedash > grab game, guaranteed combos and pretty much guaranteed KOS, and a turtle.
He has a poor shield that doesn't matter against Mewtwo except in cases of good neutral airs... M2's forward air is a killer, gimpable and fairly predictable recovery because it is more vertical than horizontal.
OFFENSE Grab down throw and wavedash forward. G&W has a very poor tech and you can punish people for DIing away at low % pretty well. If he jumps out of it then... that's all you got I guess. Charge your Shadow ball when you can. If you know he wants to play for a bucket, it doesn't matter. He needs 3 to use it, it is difficult to land on a good player, and you can punish him HARD for it. It doesn't go away when he dies, but the main thing to keep in mind is that it is laggy when he catches something and his
head is always vulnerable. Time you FC Shadow Ball to wave up and over his bucket and land on his head.
You can get punished for down tilting at low percentages and even medium percentages, so use sparingly on his ground game unless you want to eat his even stronger and better down tilt that can combo you harder. Use baby shadow balls with your approaches, try to get inside of him by moving around with good wavedashes and teleports and get those grabs on him. Mewtwo doesn't have very many combos on him aside from the bread and butter combo on floaties. (D-tilt, Forward air, up air.) Neutral air on his poor shield does well against him though if you get him onto a platform or attack him out of your shield from poorly spaced/attacks on your back.
DEFENSE
Even though G&W has air superiority and ground superiority, he is still pretty linear. If you can read his approach, punish and bait attacks, it can give you the openings you need to chip in damage for your up throw KO. You can also try to use Confusion' spacing to your advantage by using it as a counter to long forward air attempts by the G&W, safely out space down tilt, or calling his attacks out of shield with your own confusion out of shield. You have to throw it before he throws his aerials though.
G&W has guaranteed grab KOs and his best killers are neutral air, forward air, forward smash, and at higher percentages sweet spot down tilts. Fortunately G&W's SHFFL game doesn't give him free grabs, his game revolves around spacing from the shield grab, not so much the hit stun. So most of his KO moves can be avoided with good play, and you can keep chipping away at his percentage until he's in the danger zone.
EDGEGUARD
Basically, if you have him in a position where he's coming very high, there's not much you can really do since he beats you in the air. If he's in a position where he's pretty much forced to use his double jump to help his recovery, then you have something.
You jump out at him backwards just out of range of his forward air, but you want to be able to throw your back air at anytime. Bait his cover aerial and/or attack him when there is an opening, that one back air will probably be all you need to **** his momentum and then it's just a simple ledge stall to roll for the KO since he needs that double jump for horizontal mobility and his recovery is mostly vertical. His only saving grace is that he is kind of floaty. By pressuring him with the threat of back air, even if you trade, you should get something out of it unless you're in KO range yourself. You also have better aerial mobility, so it should be doable.
Just be mindful of early Up B's and attempts to land on the stage from the free fall. His recovery isn't HORRIBLE, it's just predictable... like Marth's in a sense.
Down Smash if you can't get the edge hog and be ready for possible tech and just repeat.
LAST THOUGHTS
Get grabs, don't bite on crouch cancel down tilt. You can't crouch cancel grabs, and you get free down tilts if he tries to at higher percentages. Try to make use of that poor shield to the best of your ability, but it's difficult when you don't have the tools. Avoid his KO moves which only 2 can be comboed from a grab. Avoid the second hit of his down air, and don't bite on that either because a down tilt usually follows unless you know you can beat it with your shield grab. Keep moving, keep getting him to make mistakes, and get him on the floor, get him get him on the floor, WHAT! Tech chases will get you the down tilts you're probably looking for. Back throw by ledges at middle to higher percentages, and remember your up throw for KO.
Don't try to challenge G&W directly, punish lag when you can. You can't really beat his down air head on, so don't try. Hit him from the side if it is obvious, and keep that Shadow Ball handy. It can hit through his small shield when you need it and it can hit his head. G&W has a bad roll so punish him for that too.
. So for her it's really 119%/128%. I’m also getting the same result with Jigglypuff that you are now as well. 
