So as some know Marie is actually totally playable in the 24th and 25th challenge. However as those people might also know is that there is no list of commands. To beat the challenge it's important to know how to input the best of her arsenal. Thing about Marie is that it'd be hard to put her moves into specific categories like specials and neutrals, because every input on it's own and with a directional input is a different move, even slightly. So they will be categorized in the directional input. I don't know why I'm making this sound so professional, this is almost useless info. But if you want to know, carry on.

LP - Shoots a skull close to the ground. It travels fairly slow and moves up and down.

LK - Shoots a skull close to Marie's head which loops around like a boomerang.

MP - Shoots a skull close to the ground. It travels considerably faster and moves up and down.

MK - Shoots a skull close to Marie's head. It travels quickly and moves up and down on a more shallow angle.
HP - Shoots a skull from Marie's torso. It moves quickly, and moves up and down at such a shallow angle that it barely matters.
HK - Shoots a skull close to the ground. It moves quickly and moves up and down again at an extemely shallow angle.

Not bad attacks, but many others overshadow them.

LP - Marie points forward and moves forward quickly a short distance. Effectively Marie's dash.

LK - Exactly the same as LP. Marie's dash.

MP - Marie raises her arms and blinks. I have seen no use for this move. Occasionally when hit by a move when using this one, the Skull Heart will glow purple, but again it seems useless.
MK - The same useless move as MP. Or maybe MP is the same as MK?

HP - Marie dashes backwards. Same distance, same speed as the forward dash.

HK - Again it is Marie's backwards dash.

Essentially up is your dash input. Don't waste your time trying to figure out what what MP and MK do.

Trust me it's not worth it.

LP - Summons the dive-kicking skeleton lady. She will descend on the opponent no matter your distance from them.
LK - Summons skeletons to grab the opponent from the ground. It holds them a moment and then tosses them away from you.
MP - Summons the blade skeleton from a low height. Travels quite quickly, and you can spam him too.

MK - Summons the exploding skeleton in front of you. It will sit around for about 5-6 second before crumbling away. However, if an opponent approches or touches it, it will explode. You can summon them fairly quickly, and they will stack.
HP - Summons the tommygun skeleton. He shoots about 5 bullets and provides some good knockback for spacing. He can be resummoned fairly quickly.
HK - Exactly the same as HP. If there are any differences, I haven't noticed.

These are your skeleton summons. They are quite useful, especially the grab.

LP - Summons four skulls, each with a different direction. One from each height, and one boomerang. Very nice for spam.
LK - The same as LP. Four skulls, four directions.

MP - Here it is folks! The bread and butter of Marie. The really big bone snake things. This is the horizontal variation. It can be spammed very easily. Thank goodness Marie doesn't make use of that as a boss.
MK - Exactly the same move as MP. Skull worm things.

HP - If the MP and MK were the bread, HP and HK are the butter. This the diagonal version of the attack, and can be spammed just as easily as the horizontal.
HK - As I said, this is the same as HP. I just want to keep the format consistent so this entry is here.

Use forward inputs a lot. They are good.

All of the Backward Inputs are what I'd call Marie's taunts. LP, LK, MP, and MK all have her point forward and say one of her taunting dialogues. As for HP and HK, they have her point forward, but she says nothing.

Don't press back.

As you enter Marie's second phase, some moves will be removed, and some will be added. All changes are listed below.

Removed: Forward MP, MK, HP, and HK. So unfortunately, the skeletal steamrollers are gone.

Added: Goddess attacks. Unfortunately again, the attacks listed above are not replaced by the goddes attacks. Hitting those inputs with forward will now do nothing. The inputs for the goddess attacks are as follows:

Hold Forward, Press Back + LP - The goddess jabs at the opponent. Crazy knockback.

Hold Forward, Press Back + LK - The goddess leaves your side and appears behind your opponent, jabbing them and sending them sliding towards you. Nothing personnel, kid.

Hold Forward, Press Back + MP - The goddess travels from under you and appears beneath your opponent, hitting them with an uppercut.

Hold Forward, Press Back + MK - The goddess ascends and then descends straight on top of the opponent with a kick.

As for changes with the third phase, you revert back to the first phase's moveset and almost all lag is removed from your moves. Spam city.

However if you do the challenge right you'll most likely never drop beneath first phase, making this info all the more useless.

I hope someone finds this interesting and that maybe this guide helps a couple people having trouble with these challenges. This took a lot more time and effort than it'd immediatly appear. Good luck, and peace out.

Oh and if anyone ever finds out what that one useless move does, I'll be very disappointed.