Twilight Sparkle: This is where the letter said to meet up. So where.
???: Miss Sparkle.
Ts: Huh? Who..who are you?
???: Allow me to introduce myself. I am Noire Ace.
TS: Wait.You're Noire Ace. This cannot be right.
Noire: It is. Shall we begin.
TS: I cannot duel you. You're an earth pony. You cannot use magic for this type of duels.
Noire: If that the case, you wouldn't mind if I make the first move. Launches an energy wave.
TS: dodges.
Noire: Words of wisdom- Do not underestimate your opponent and expect the unexpected.

This is the first time both Twilight Sparkle and Paradox interacted with each other. Still, why would he challenge Twilight to a duel and disguised as an earth pony no less?