I finally beaten Cynthia in Brilliant Diamond. She's made a mistake of switching from Milotic to Garchomp. My Weavile Skrolk, managed to use avalanche to get her Garchomp in half health before she falls. It all comes down to Milotic and my girls, Lopunny and Octillery. Maddy, the Octillery finished off Garchomp and all that's left is her Milotic. After a while, Milotic kept using mirror coat until she runs out of PP against my Octillery. Through struggle, we finally beat her! I'd say two of my favorite pokemon had help us so much, I wish I could hug them both. The rest of my team did their very best and helped these two to finally take down Milotic. Milotic is THE REAL FINAL BOSS!