DogWater

I was underprepared and it took me many attempts to beat the last boss to the point where I had to change some movesets just for the last boss. My team 1. Lvl 61 Meowstic Ability: Prankster, Moves: Misty Terrain, Fake Out, Light Screen, (Was Reflect First)Thunder Wave 2. Lvl 100 Gardevoir Ability: Trace Moves: Moonblast, Thunder Wave, Destiny Bond, (Was Psychic First)Taunt 3. Lvl 100 Silvally I switched between Electric, Steel, and Fairy memory and mostly used Multiattack 4. Lvl 100 Charizard with Charizardite X, Moves: Power-Up Punch, Flare Blitz, Dragon Claw, (Was Brick Break First) Flame Charge 5. Lvl 100 Swampert with Leftovers, mostly just Earthquake spammed but used Ice Punch sometimes too 6. Lvl 100 Garchomp with Dragon Fang, Outrage or die, with a few Iron Heads and a Stomping Tantrum

Hey I just taught my Keldeo secret sword but it didn't change to resolute form. Is there another step to make it change forms? I saw that Resolute Form was in the added sprites so I thought it was in game.