There is only one champion in English translation. Please don't use translation software. Most grammar is wrong. Please use your wisdom. Thank you.

There is only one champion! It was translated according to your original intention, and both spoken and written language are not bad.

Please explain your supplementary question:

There can only be one champion. The meaning is slightly different. "There can only be one champion" has one more word "can".

How do you want to use it in the paragraph? It seems that you think this is too colloquial, but there is only one way to express some meanings, and there is not much change, whether it is spoken or written. Self-defeating Chinglish mostly comes from people who are whimsical.

Some questions. . . There can only be one answer-the correct answer!