I know there are not a lot of Mantis Clan Cards yet available, but we do have four that we know of, and three that can be fielded within the same deck build. So while it is not a lot to go off of they do have a recurring theme, which is Fate growth for a price. Honestly it could be a fun design space to play with, but with the current game what cards best enhance that theme, or build alongside it. I'm inclined to look to either the Dragon Clan with their fate manipulation (which keeps me to just two Mantis at the moment), Phoenix Clan (three and shugenja friendly), or perhaps Crane (again three, but instead more bushi). I'm not sure which would work best, but I feel that Crab would be the best splash for any of them, or perhaps scorpion as a splash.
So I suppose I'm asking for thoughts, deck concepts, and how you would play the Mantis Clan as they are currently.