The new Legendary Pokémon available in the Pokémon Sword and Shield DLC expansion, The Isle of Armor, is Kubfu. This is the starting form and will evolve into Urshifu, which you can transform into Fighting and Water type or Fighting and Dark type depending on the choice you make in the game. After making your decision and progressing through the available turns and evolves Kubfu, you can unlock Urshifu's Gigantamax form.
You will have the opportunity to do this after completing the final battle on the Isle of Armor atop your chosen tower, where you have defeated the Dojo Master Mustard. At this point, Kubfu will have evolved into Urshifu. You must return to the Master Dojo and Hop will appear, informing you that he is on the Isle of Armor to find out how to Dynamaxing Pokémon. You and Hop will need to complete the next step for Urshifu to unlock his Gigantamax form, which requires you to get Honey to add to Max Soup.
Go to Forest of Focus on the Isle of Armor at one of the entrances to meet Hop. You'll enter a cutscene telling Hop about finding a Petilil, and he evolves into a Lilligant, the Pokémon you've been looking for. You have to find the parents of the Pokémon. You don't have to venture too far. You can search the area for a Lilligant and then bring it back to where Hop and the Petilil are waiting for you.
After receiving the honey from these Pokémon, you must obtain it from Applin. Follow the path through the same forest and you'll find an Applin in the middle of the path, which brings you to another cutscene. You and Hop scared him into a tree. When you lower it it hits you on the head, but you get the Pokemon's honey.
The next stop is an island next to the giant water tower on Challenge Beach. Race there and when you get to Challenge Beach you can ride your Rotom Bike to Honeycalm Island. You will find Hop in the center. The Pokémon you are looking for on this island is a Vespiquen. When you try to chase one from the tree in the center of the island, you make it worse. Now you have to fight a Dynamax Vespiquen, a Bug and Flying type. You will receive Max Honey after the battle.
Take it all back to the Master Dojo, and you can now give it to the Max Urshifu Soup. However, you will still need Max Mushrooms to receive the soup. You can get the maximum amount of mushrooms by raiding the Isle of Armor as much as possible.
