Andy attacks with Aurelia, the Warleader and a Runeclaw Bears. After Aurelia triggers, he attacks with those creatures again.

Can he cast the spell under Windbrisk Heights?

No, he cannot.

In order to cast the card hidden away under Windbrisk Heights, Andy must have declared three different creatures as attackers over the course of the turn. Attacking with the same pair of creatures again means Andy's only attacked with two creatures this turn.

Daniel Kitachewsky
L4, Paris, France
Rules NetRep