This question is more for papi but answer as mod if you desire; if papi had to take on any mate, and I mean ANY; dragon, griffon, bull, alicorn, pegasus, etc., what non-changeling would type would she pick?
Most likely a unicorn. Seeing as Papillon was formerly Fleur de Lis, and there tends to be a general favoring of unicorns in Canterlot it makes the most sense.