Previous characters (click to view, Link done by georly)
Disclaimer: I can't read Japanese, so I may have missed certain effects that are hard to test (such as shieldbreaker properties) and I don't know the names of the custom moves so I've completely made them up.
The first of today's 2 mushroom kingdom denizens, Bowser Jr. (+Koopa Kids) is a really great addition to smash and I've wanted them since the Ninka/Vaanrose leak, the way they were described was just too brilliant for it not to be true, and they're even better in game than I imagined.
Neutral Special 1 (Steely Cannon)
The Koopa Clown Car (KCC from now on) opens up it's mouth and extends a cannon, charging until you either release the button or it reaches full charge, at which point it will shoot out a large metal ball.
The travel distance and initial damage are determined by how much you charge the move, with the damage degrading as the ball travels.
At close range, it will do 7% uncharged and 18% fully charged, the ball will travel straight for the most part until it reaches it's max range where it will drop like a, well, like a steel ball really.
As it travels, the damage goes down to 4% uncharged and 13% full charged, once the ball hits someone or hits the ground, it will bounce once but it will no longer have a hitbox.
If it doesn't hit anyone and starts falling, it will still keep the hitbox until it reaches ground, so you could use it to edgeguard below the stage line, though it's not particularly good at it.
The uncharged distance is just under halfway across Battlfield and the fully charged distance is just under the entire length of Battlefield, hitting a projectile with the ball will destroy the other projectile but cause the ball to instantly start dropping, regardless of whether or not it's travelled the full range yet.
Neutral Special 2 (Piercing Steely
This version of the move seems to have the exact same stats as the other move, but the metal balls will do less damage and pierce.
Uncharged starts at 4% and degrades to 2% whereas a full charge does 10% and degrades to 5%.
Unfortunately it will still fall if it hits a projectile, so it doesn't seem to have much application in a 1v1 setting.
Neutral Special 3 (Vortex Cannon)
This custom trades damage for a pushback effect.
The range isn't as large as the default, going just over halfway across Battlefield at full charge and just over a third at minimum charge.
The pushback effect is pretty standard, but I'm not really a fan of these moves, if you prefer this sort of thing then this is the move for you.
Side Special 1 (Koopa Clown Kart)
The KCC sprouts little wheels, backs up a little bit and then drives full speed ahead, doing 4% damage to anyone it hits, at the end of the travel distance (which is just over the entire length of Battlefield), the KCC will spin out, doing 12% damage and skidding about a quarter of the way across battlefield.
From the moment the KCC starts moving forward, it can be cancelled into one of two things; a jump or a spin out. Pressing the jump input will result in a jump (which allows for some interestingly spaced aerials considering it moves you a bit back first and you keep the momentum of the KCC travelling forward) and pressing either back, B, A or Grab will cause it to spin.
You can also press forward whilst driving to increase your travel speed and increase your distance a bit.
The knockback from the initial part of the move is vertical, and you can basically hit confirm it into jump cancelled aerial(s) at low to mid percentages, whereas the spin out does horizontal knockback that is much higher, able to kill Samus at 125%.
This move is such an incredibly versatile part of Bowser Jr.s moveset it's not funny, it's a KO move, a combo starter, a fake out tool, it's insane and you'll have to get used to seeing a lot of Bowser Jr. players use this move quite often I think.
Side Special 2 (Super Spin Kart)
The KCC retains all the same abilities as the previous move, but it moves slower, travels less distance, the jump cancels don't send you up as high, it does less damage whilst travelling BUT, the spin out has been turned into a multihit move.
The initial drive will only do 2% now and the spin out will do 9% if all hits connect, the final hit does increased horizontal knockback, but it has much less KO power than the default, so I think this move ends up being a downgrade overall, unless there's some other property I'm forgetting (maybe the multihit means it eats through shields?)
Ah, it seems that if you spin out in midair, you'll barely lose any vertical height, so it could be useful if you need a better horizontal recovery.
Side Special 3 (Koopa Clown Steamroller)
This time, the KCC winds back a little further, travels faster (and can't be slowed down by not holding forward), does no damage on the spin, can't jump cancel as high, does no damage when used in the air and only goes as far as the second Side Special.
But this custom will bury anyone it touches in the ground if both players are grounded, doing 8% damage and setting them up for another attack.
Up Special 1 (Emergency Eject)
Bowser Jr. ejects himself from the KCC, causing it to come crashing to the ground with a forceful explosion, the KCC will do 5% on contact and the explosion will do 13% and decent diagonal knockback that kills Samus around 135%.
Whilst in the air, Bowser Jr. can swing a little hammer around that does 15% damage and can kill Samus around 115%, so he's almost just as good without the KCC as he is with it! Though getting hit won't refresh your recovery, so be weary of getting carried off the stage.
When he returns to the ground (with very little ending lag), a new KCC will spawn out of nowhere, he must really go through these things, and they can't be cheap to make!
Up Special 2 (Meteor Crash)
In this variation, travel height is sacrificed in favour of a Meteor Smash during the startup of the move.
It only does 3% on collision and 10% with the explosion, and the distance you travel is just over half as much, but the fact that it's a meteor smash more than makes up for it imo, just don't forget that this move is also your recovery and end up going too deep.
You can still swing your hammer whilst airborne and it doesn't actually seem to be any different to the default one, doing 15% damage and decent knockback so no nerfs here to compensate by the looks of things.
Up Special 3 (Explosive Launch)
For this one, the KCC flies up with you for the first part of the move, exploding at the apex and sending whoever is inside crashing down to the ground.
You do 17% damage on your way down and significant knockback that's able to kill Samus around 135%, which is off the top as the knockback is vertical, so that is pretty high knockback.
You can cancel the downwards attack into a hammer by pressing the A button, which means you don't travel down so fast and can actually get a bit of horizontal distance out of it, otherwise it's much harder to use as a recovery as it must be done below the ledge, if you're not near enough you'll be sent straight down.
Also worth nothing is that you can't grab the ledge on the way up, only on the way down, so make sure you get the timing right with this otherwise it's going to be very easy to gimp you out of your recovery (you should be fine on the way up though, as getting hit during that portion of the attack will refresh it).
Down Special 1 (Mecha Koopa)
A hatch opens underneath the KCC and a Mecha Koopa pops out, the little guy will automatically walk across the stage in the direction you're facing, turning around if it meets a ledge.
If it collides with an enemy (which does 2%), it will jump in the air and explode, whereas if it travels it's max distance without meeting anyone, it will spark for a second or two and then explode.
The explosion does 9% at the center and 7% around the outside, and the diagonal knockback is not really useful as a KO move (only kills Samus at 250%), but the move is meant to be more for stage control, I don't see a reason why you shouldn't almost always have 1 of these on stage (and you can only have 1, trying to use the move again won't do anything).
After being ejected, the Mach Koopa falls quite fast until it hits the ground and starts moving, so it can actually be used to help edgeguard, but it's much harder to hit with due to seemingly having a smaller hitbox whilst in the air.
Watch out though, it can be picked up and thrown back at you for the same amount of damage.
Down Special 2 (Lazy Mecha Koopa)
This Mecha Koopa can't (or won't?) walk, but it will be flung out of the hatch with increased horizontal speed and a slightly lower falling speed, meaning you can use it as a horizontal projectile rather than a vertical/stage control projectile.
If it falls from a certain height, it will bounce the first time it hits the ground, otherwise it will instantly start sparking and then explode..
The explosion only does 4% damage this time around and hitting a player with it will do an extra 1%.
I assume it can still be picked up and thrown, but the fact that it doesn't walk anymore makes this a bit hard to test.
Down Special 3 (Mega Mecha Koopa)
A much larger Mecha Koopa comes out the hatch, it travels slowly, only covering about a quarter of the distance the default one does and it will no longer explode on contact (unless picked up and thrown) only when it reaches the full travel distance will it explode.
And the explosion is much bigger, doing 15% damage and knockback that can kill Samus at 150%.
This version can no longer be used to edgeguard as it can't hit people in the air, and picking it up and throwing it will do 1% extra damage.
Final Thoughts
Bowser Jr.s specials in this game are super cool, especially his side B and down B, he's also one of the first where I wouldn't actually want to change many of his defaults, the only one I'd change is the recovery, swapping it out for the Meteor Crash version, just to give the guy even more KO power.