"ten years to grind a sword, just to win the championship today." This sentence expresses a long period of hard work and waiting, which means that a person is waiting for an opportunity to show his strength after a long period of hard work and accumulation.

The writing of this sentence can be referred to as follows:

Grinding a sword under the window for ten years just to win the championship today.

I have been working hard for ten years and have been honing my skills and abilities. Now I finally have a chance to show my strength to the world.

I hope this sentence can help you and wish you all the best!