Testo originale - Inglese - i'm the one and only, in heaven and earth

Hi Sikko,
The meaning is a little different, but this reminds me of the phrase the Buddha is reputed to have said when he was born:
天上天下、唯我独尊
It roughly means:
"In Heaven and Earth, only I am the one to be respected."

PS: I didn't translate your original text, because if you say that literally in Japanese, people will just wonder why you're saying something completely logical, and completely meaningless...
Of course there is "only one you": did you think there were two of you?

I think, 天上天下、唯我独尊 is right !!!!