Rabbid Luigi is THE character to have. His Dashes will allow others to heal from attacking enemies PLUS with the Round Shield Shocker he will 100% Stone enemies struck. Weaken is fine and Super Barrier helps him to be a target to attacks and Super Effects. Just make sure he doesn't die.
The first ultimate challenge has lots of midbosses. Rabbid Mario can destroy them with ease but don't be too reckless.
The second ultimate challenge is about surviving a really long battle. I find Yoshi to be super helpful because with Super Chance and the Golden Rocket he will 100% Ink enemies attacked, preventing them from using their weapons. Combine that with Mario's M-Power and you've got yourself a heavy attack.
The third ultimate challenge involves traversing a very large map to reach an Area. This is Luigi's time to shine! He has the best movement and can can divert enemies' attacks with his sentries. Just be very careful with him because of his low HP.
The fourth Ultimate challenges involves escorting Toad across a MASSIVE battlefield. I'd recommend Rabbid Peach because she can heal Toad if he gets attacked. Have the heroes heal from Rabbid Luigi's Vamp Dash so that you don't waste necessary heals with Rabbid Peach. Take your time in this one - get rid of the enemies but don't go TOO slowly. There's a part where the path branches out. In this section, I'd recommend taking the long route (with the explosive cover blocks) because the shortcut has lots of Valkyries and it's difficult.
The first ultimate challenge has lots of midbosses. Rabbid Mario can destroy them with ease but don't be too reckless.
The second ultimate challenge is about surviving a really long battle. I find Yoshi to be super helpful because with Super Chance and the Golden Rocket he will 100% Ink enemies attacked, preventing them from using their weapons. Combine that with Mario's M-Power and you've got yourself a heavy attack.
The third ultimate challenge involves traversing a very large map to reach an Area. This is Luigi's time to shine! He has the best movement and can can divert enemies' attacks with his sentries. Just be very careful with him because of his low HP.
The fourth Ultimate challenges involves escorting Toad across a MASSIVE battlefield. I'd recommend Rabbid Peach because she can heal Toad if he gets attacked. Have the heroes heal from Rabbid Luigi's Vamp Dash so that you don't waste necessary heals with Rabbid Peach. Take your time in this one - get rid of the enemies but don't go TOO slowly. There's a part where the path branches out. In this section, I'd recommend taking the long route (with the explosive cover blocks) because the shortcut has lots of Valkyries and it's difficult.
Hope this helps! *wink*