Describing the prophet in a positive context but with a negative word: Blasphemy?

Assalaamualaikum.

I wanted to ask you that what’s the ruling on the person who uses the word باغی=rebel (NauzuBillah) for Prophet ﷺ and says that He ﷺ was the Biggest باغی = rebel because he did بغاوت / Baghawat against Kuffar/non-believers in Makkah. Furthermore He says that he is using the term in positive sense and to uplift the status of Holy Prophet ﷺ