The Ultra Bonus was "Cards Against Humanity," or more specifically, cards from the game "Cards Against Humanity."
We had thought it was a good, contemporary theme, but it stumped everyone until the eighth hour freebies. Maybe the hundreds of available card topics were too eclectic and varied to pick just 21 of them? Given the options, we had considered doing more than three per hour, but didn't want it to get too obvious. There was also a team debate about point values, because we didn't want to throw the contest balance out of whack if a team solved it on the first set. That debate was certainly a very useful thing for us to have had.
One of the teams this past Saturday even did the "Show us what a music star who died in 2016 has been doing since" Action Trivia by filming a video of themselves holding cards and playing Cards Against Humanity. But they didn't solve the Ultra either!
Here are the clues: