It looks like players can get to know the five Champions in the past and the present, and play as these Champions in addition to Link.
The Legend of Zelda: Breath of the Wild DLC Pack 2 - The Champions' Ballad is now available for Nintendo Switch and Wii U worldwide. As long as you have the expansion pass purchased, Champions' Ballad should drop into your game as an update.
Aonuma shared the Master Cycle Zero would be made available once players "overcome all of the challenges in the new DLC" and that it will assist in players' Hyrule adventures in "unique new ways". "What you all just saw at the end of the trailer is a reliable partner for Link".