His name is Narayana.
He is called Madhava.
He is called Ajit because no one can defeat him.
It seems that in such cases we're talking about words as words, and some kind of use/mention distinction seem to be required. Italics is already reserved for foreign terms in my text, therefore I'm considering using quotation marks.
However, it seems that the common practice is not to emphasise names in such cases at all. Example: https://ell.stackexchange.com/a/260744/147879
What is the grammatical norm for this?