Can you have a different Legend in your sideboard than in your main deck?

Ruling: No, you cannot have a different Legend in your sideboard. You must use the same Legend throughout the tournament.

Nuances:

• You can change your Chosen Champion to one from your sideboard or main deck that matches your Legend
• A player may not change their Legend or Battlefields at any point after deck registration
• Sideboard limits on copies of named cards apply to the combination of Main Deck and sideboard