If you liked the C: The Money of Soul and Possibility Control anime, the Anime-Planet community thinks you'd like:
One night, Madoka has a terrible nightmare – against the backdrop of a desolate landscape, she watches a magical girl battle a terrifying creature, and lose. The next day, the teen's dream becomes reality when the girl – Homura – arrives at Mitakihara Middle School as a transfer student, mysteriously warning Madoka to stay just the way she is. But when she and her best friend Miki are pulled into a twisted illusion world and meet a magical creature named Kyubey, the pair discovers that magical girls are real, and what's more, they can choose to become one. All they must do is sign a contract with Kyubey and agree to fight witches that spread despair to the human world, and in return they will be granted a single wish. However, as Homura's omen suggests, there's far more to becoming a magical girl than Madoka and Miki realize...
While these series may seem miles apart, they both focus on a main character that can't completely decide which world they want to live in and what they want to do with it. Eventually, they finally decide and cause a very similar ending in each. Without spoiling, all I can say is if you liked the ending in one, or the struggle to decide what's right and wrong, and who to believe, it's definitely worth giving the other one a try.
WIXOSS is a card game that's popular with teenagers. Supposedly there exist "Rulig Cards," female character cards with wills of their own. Special girls can hear the voices of the Ruligs, and those who possess them are called Selectors. These Selectors have card battles in a dimension that other humans cannot access. It's said that whoever triumphs in these battles will have their wish granted. Ruko Kominato is the latest girl to find a Rulig card. She names hers Tama, and without any further explanation is thrown into her life as a Selector.
If you're a fan of the battles in WIXOSS or C, then this is a rec for you. There are a few differences between the two shows, but the fighting is pretty much the same. Holders of mysterious cards do battle by summoning a supernatural being from inside the card. The holder then commands the being, and if they win, they are rewarded. If this kind of battle system is what you're looking for, then look no further.
In a bizarre fantasy world, students known as meisters are trained at the illustrious Shinigami Weapon Meister University; but the tools they wield are no ordinary weapons! Each meister is paired with a human-like being who can transform into a weapon at will; and after defeating a pre-kishin - a human whose soul has darkened - the weapon eats the soul within it. A meister's ultimate goal is to collect ninety-nine pre-kishin souls and one of a witch so that his or her partner will become an all-powerful Death Scythe. Maka and her partner Soul Eater; Assassin Black Star and his partner Demon Blade Tsubaki; and Shinigami's son Death the Kid and his partners the Demon Twin Pistol Thompson Sisters each vie for their ultimate goal, but plenty of challenges and adventures lie in their way!
If you liked the concept of humans and sentient weapons working together in battle, and the secret organizations they work in, then you’ll probably like both of these series. They both also talk about the ethics behind how a weapon is treated, and feature heavy plot mixed in with action.