This is the kind of thing that should not exist. A one-off crossover OVA that was never sold, only handed to fans who actually bought both shows on laserdisc, now lost to time and streaming's amnesia. Two separate series colliding in a comedy epilogue that nobody talks about because almost nobody ever saw it, which is exactly the only reason to care that it happened at all.
A single-episode OVA that serves as a parody epilogue to two magical girl series, Mahou Tsukai Tai! (Magic User's Club) and Shamanic Princess, which came out around the same time. Triangle Staff produced it and Bandai Visual released it. It was never sold in stores. Fans could only get it by buying all six first edition laserdiscs of each series, twelve in total, and mailing in proof of purchase before a deadline. The creators offered it as a special extra for those fans, wrapping up both shows with a comedic fantasy send-off.