The Great Kabai Sengh: You're not immortal. I know your secrets, Phantom.
The Phantom: Take them to your grave, Kabai Sengh.
Phantom's Dad: Hey, Kit. I like her.
The Phantom: Thanks, Dad.
Xander Drax: All right, what's your name? Why do you want that skull so badly?
Kit Walker: Kit Walker.
Xander Drax: Huh, and who is Kit Walker?
Kit Walker: I am.
Xander Drax: And what about the skull?
Kit Walker: It'd go well with my drapes.
Xander Drax: My name is Xander Drax.
The Great Kabai Sengh: What?
Xander Drax: X-A-N-D-E-R D-R-A-X. Xander Drax. Begins and ends with the letter X.
Xander Drax: History is about to be made and you're all a part of it. Not an equal part, of course, but an important part nonetheless.
Sala: The Phantom helped Diana to escape. I think he's in love with her.
Xander Drax: Oh really? This is getting more interesting by the minute. Why do you say that?
Sala: Because he could have had me... but he picked her. That could only be love.
Xander Drax: Or simply bad judgment.
The Great Kabai Sengh: Now let me see... When was the last time we had visitors here below the ocean, deep in the bowels of this uncharted volcanic island? Never! Congratulations! You pathetic doomed fools are the first.
Xander Drax: Quill, would you please show Mr. Walker up to the observation deck and make him talk?
Sala: I claim the body when you're done.
Answer: She was preoccupied trying to escape from the bad guys and annoyed that a guy in a purple suit, was trying to save her, when she said, "I can do it myself." It was most likely later, in New York, when the met face to face. Kit and Diana, when she put two and two together. Again was too preoccupied trying to save the world to pause and confront him.