Concept: Someone starts of with one sleight or effect. The next person adds on something, then the next one adds something and so on.
The catch is one has to be able to perform what the one before him/her has done in order to further continue the video. So the challenge itself would depend a lot on how high the people set the stake for the next person.
For visual, action sleights, this video could work and it won't be that long.
Then comes that one person that throws in an effect that requires 3 deck switches...
A step further
A world where artists have been contributing to the art chain for decades. It has gotten to a point where when someone is being named, that person named mus be a child, for it usually takes the child a few decades until he is able to execute all of the necessary actions.
This chain can include actions such as: paint a house, kick a baby, kill a rat, eat your finger, perform at the opera in Vienna - depending on how absurd you want to make it, you can transform this in a Bucket List of sorts, where the respective individual must do all the actions one after the other in order to pass it to someone else.
Or you can make this a more technical orientated sketch, where an artist must perform artsy actions one after the other - make a beat, drop some rhymes, run on the treadmill an maximum speed, smoke a spliff, sketch fast a human being - this could be developed into a video challenge with youtube artists gathering their own team and making a video showing their end result.