Deee's feed

Can be from Asura manga
About knights / sorcerers
Training to become stronger
He died and went back to the past?
Sword with fire maybe not sure about this one

The only thing I remember was that he was training hard with other students/ peers and that when they needed to test his learning through aura he overcome his fear.

His teachers are strong. The teacher during the test has green hair.

Thanks in advance