Marie's interesting. I've played about 40 matches with her so far, and she's a zoner, but she does it kind of indirectly compared to the others. I guess her usual tools are the storm cloud, the chocolate thing and her 214C/D eye that sucks opponents in. That eye, in particular, seems to be what she has to use in order to give herself some room to pull out the presents. Her Persona normals are pretty good and cover a wide area with relatively fast start-up.
Most interesting part is the weather mechanic, which influences her status and moves. She can control the weather by landing her 236236C/D super, and holding A, B, C or D once the cards are spinning.
A (Aeon) will result in the sunny weather with an explosion, which is also the default at the start of a match. Not sure if it influences anything else yet, but it increases the damage of the super's A variation.
B (Emperor) will result in the cloudy weather with a thunder strike. This will cause all of Marie's electric based moves (e.g. her throw, her DP and the B super itself) to inflict the opponent with paralysis. Additionally, when she pulls out the storm cloud out of her bag during this weather, she will pull two out instead of one.
C (Empress) will result in the rainy weather. Marie will slowly regenerate HP during this weather. This will also significantly increase the damage of the C variation of her super.
D (Star) will result in snowy weather with a giant ice block falling on the opponent. Marie will slowly gain SP during this weather, but unlike Elizabeth or a Victory Cry Junpei where it constantly increases, she gains SP in chunks of 5 SP per ~3 seconds. Additionally, the D version of her super will now freeze the opponent.
The weather will change between rounds. Not sure if it's completely random, or if there are conditions that will determine what the weather will change to at the start of the subsequent round.