Learn Italian: Lei gli ha chiesto chi è l'uomo affascinante. - She asked him who the charming man is.

When you report a "Wh-" question (who, what, where, when, why) in indirect speech, you just use the question word itself to connect the two halves of the sentence. You don't need to add che or se. She asked who = ha chiesto chi.

Since the first verb (ha chiesto) is in the past, why is the second verb (è) in the present tense?

Even though the asking happened in the past, the fact she was asking about is still true right now. The original direct question was "Who is the charming man?" (Chi è...), so we can keep the reported verb in the present tense to show it's a current reality.

Why do we use gli instead of lo for "him"?

In Italian, you ask a question to someone. The verb chiedere requires an indirect object (chiedere a qualcuno). Gli is the indirect object pronoun meaning "to him", whereas lo is a direct object pronoun.

Would affascinante change if she was asking about a charming woman?