Ok, since I'm going to sleep soon, I'll post as much relevant info as I can and leave it up to everyone from there. Also it would be nice to know Ryu's AP. Magilou is >24 Megatons, as I said before.
First, how she fights:
She generally fights by casting magic from a distance and, while she may not take things too seriously, in a fight to the death she will fight to the best of her ability, she isn't a close range fighter so moving away or casting a spell right away is fairly likely.
So, some relevant abilities:
Gravity Manipulation: It's the type that holds you opponent in place while you're free to do things, she can set traps that do this too, with Gravity Mine.
Life Manipulation: A property of many artes in general, she gets healed while fighting
Summoning: She can summon the spirits of 49 normin (A type of malak, comparable to her) and rain them down on the opponent, she can also summon Guardians, a type of paper creature that she can also fly around on like a hoverboard, they can also change sizes
Stat Amping/Reduction: This one is actually fairly relevant, it's at least 50%, I believe it can go up further, it's a property of most of her attacks, it works on enemies when hit and on herself when she casts, so Ryu might, say, find himself suddenly losing 50% of his physical strength or Arte Attack (In this case, that would mean techniques like the Hadouken), also, she can slow down the opponent fairly significantly (About 4x)
Poison Manip: It's there I guess, a property of some artes, it damages over time.
That's about all I can think of for now.
