For 4 points $O,A,B,C$, let the reflection of $O$ across $BC,CA,AB$ be $P, Q, R$, resp. Then the circumcircles of $BCP,CAQ,ABR$ must intersect at a point, denote this point as $O_{ABC}$.
I'm interested in proving the following:
Let $ABCD$ be a concyclic quadrilateral, then $O_{ABC}O_{BCD}O_{CDA}O_{DAB}$ is concyclic.
I tried to prove it by angle chasing, but it seems not easy to do so.

