Can you mix different language cards in your Riftbound deck, specifically for the legend/boss monster?

Ruling: Cards within the same deck must be in the same language, but the legend can be in a different language from the main deck.

Nuances:

• The chosen champion is part of the main deck and must match the main deck's language
• The legend is separate and can be in a different language
• Different language printings may have different thicknesses due to different printers