Como Santa Elena, cada día más buena
 

Being expressed in the feminine gender, would this humorous reply to ¿Cómo estás? be appropriate for a male to use? And if not, is there a similar one that rhymes and also ends in -o?

It's a humorous reply, but it's not very elegant. :crazy:

And no, it's not suitable for a man, as it wouldn't even rhyme. But culturally, at least in Mexico, men are not supposed to praise their own looks. (That's assumed as a female characteristic.)
A man who would like to use an unserious reply might say "¿Cómo me ves?" and make a gesture of "admire me". :rolleyes:

Perhaps he can say something like "Yo, como los buenos vinos (mejorando con los años)".

Also, among men it's common to answer to "¿cómo estás?": "(Pues) aquí, como el tío Lolo (haciéndome el tonto solo)."
"Tonto" can be substituted for a bad word, but not necessarily.

I'll ask around for more alternatives... one can always count on creativity. :)

Quite true....unless the man saying it is an extravagant gay. Then I guess he can say whatever he wants.

:D

I think flamboyant is a better word choice than extravagant.