Help me find this anime

I remember watching this anime as a kid but I can't remember it's name. In this anime world people can turn this hexagonal (or maybe pentagonal in shape I don't remember clearly) looking disk thing into weapons. The main character has a giant red and yellow sword, I watched sub so I remember they often referred to it as a Lance and not a sword. The main character is Male with spiky hair, and i think his colour scheme is mostly red and he has the disk thing inside his body on the side of his abdomen.

The mc had a crush, she is I think also the one that saved his life and gave him the disk thingy. The girl can turn her disk thingy into multiple sword like arms that are connected to her thigh. She has short hair with a prominent horizontal scar across her face.

If I'm not wrong later on I think we see other characters that uses the transforming weapons but instead of the hexagonal disk they use other items.

In the end the mc fought a green villain on the moon I think.