Another challenging activity similar to Trial of the Sword

'activ':3 'anoth':1 'challeng':2 'similar':4 'sword':9 'trial':6

Master Mode or an equivalent harder difficulty mode

'difficulti':7 'equival':5 'harder':6 'master':1 'mode':2,8

The Master Cycle Zero or a similar device

'cycl':3 'devic':8 'master':2 'similar':7 'zero':4

Story content involving the new Champions

'champion':6 'content':2 'involv':3 'new':5 'stori':1

A crossover with another Nintendo franchise, e.g. Xenoblade (again)

'anoth':4 'crossov':2 'e.g':7 'franchis':6 'nintendo':5 'xenoblad':8

'callback':2 'explicit':1 'game':6 'older':4 'zelda':5

Post-game; i.e. playable content that unlocks after credits roll

'content':6 'credit':10 'game':3 'i.e':4 'playabl':5 'post':2 'post-gam':1 'roll':11 'unlock':8

This question resolves equally to the set of all answers that appear in some form in the Tears of the Kingdom DLC. As not every feature in the DLC may be announced by Nintendo ahead of time, this question does not resolve until all announced DLC has been released and I have had a chance to play it.

In the event of ambiguity over whether an answer is in the DLC or not, I may ask whoever originally added the answer for clarification; if it is still unclear, I may put it to a vote in the comments or via Strawpoll. 

Overly broad answers like "New features" or "New content" do not count, and will not be selected as correct when this question resolves.

If no DLC has been announced or released by the end of June 2025, this question resolves as 

 If DLC has been announced. this market's closing date will be changed to match the date on which the final announced DLC will be released (which, in the event that DLC is announced but not released before July 2025, may push the closing date of this question back.)