Question 94
Let $\Omega$ be the circumcircle of a triangle $ABC$. Let $D$ be a variable point on the arc $AB$ that does not contain $C$ ($D \neq A, B$) and $E, F$ be the incenters of the triangles $CAD$ and $CBD$, respectively. Find the locus of the second intersection point of the circumcircle of $\triangle DEF$ and $\Omega$ as $D$ varies on the arc $AB$.