I forgot the name of a manga I was reading. It was relatively new, I will try to summarize what I read to the best of my memory.
The main character (MC) fought a dragon and died but was sent back in time to when he was at an academy that trains their students to kill dragons. He showed the teacher he was proficient at the sword, great sword, and spear.
He became friends with a muscle head who was skilled at hand-to-hand combat. The MC had learned hand-to-hand combat from him in the future and made his own movement technique based off his friend's tribe's techniques.
Along with that friend, he also made friends with a redhead fire mage. The last thing I remember is that his brother disappeared during a fight with a dragon with control over dimensions, and was not present in the new past the MC was in.
That is all I can remember about the story.