I don't know if anyone else has tried this out, but I've used these two together twice now and it is completely ridiculous. As far as staying alive/mass damage output I would say they are unparalleled.
Combined with Toshiro the Daimyo they are really just unstoppable. Throw in 1/2 beaters and/or X 3/5 ss minions (dependent on strategy) to taste.
You've got whatever sweet minions getting Bolstered, turned into spirits, pushed around by teki o juden, and then recieving a positive flip with melee attacks (on their bolstered cb). Not to mention giving Toshi some conflict tokens if you are lucky.
When they die, Nico just replaces them and Chiaki removes their slow. Yan Lo gains Chi all the way, aiming for that final level of spirit which is the last piece of the puzzle. Now all your Bolstered, Positive Flipping minions which have been pushed closer to their position by Teki o Juden just tear through whatever stands in their path.
Combined Toshiro, Yan Lo, and Nicodem make a single 4ss Ashigaru a serious threat, even at this high points level.