Just couldn't quite decide where to pour this out, so here is a list of events you could hold:

How high can you jump without ukes help

How many backflips you can do without touching

How long you can hold a handstand for

How realistic can you make a parkour look

How well can you sketch a tree

How realistic can you make a spar look

What's the farthest you can run

Who can make the best worm dance move

Who can spin on their head longest

Who can strike the best ending pose

How many points can you get from a single hit on uke

How many joints can you remove from uke in one match

How many joints you can dm in one hit

Who can do the most damage to uke without dming or fracturing him

Who can stand on one hand the longest

Who can lift uke the highest in -30 gravity

If you have more suggestions, post them and I will update this thread.