Err ... even the worl'd most exotic and expensive lense design/elements are not immune to flare, only that the best design/optical glass and coatings can cut down or minimise.
IIRC, IF you really want superb flare control, look to the OLD, manual lenses like the T* German coated Zeiss lenses, Schnieders, Rodenstock as well as Zuikos. For example, I can almost point an old normal not premium series Zuiko or a T* coated lens directly at the sun and get minimal flare, but I can't do that with ANY of the L lenses or EF primes that I have. I'm sure that some very expensive cinematography lenses also are very resistant, but not 100% immune to flare.
One other thing I've noticed is that ultra wide angle lenses seem to be more prone to conical-point type flare as opposed to say a 50mm lense.