sounds like fun my only problem would be Im not very familiar with MK I haven't played it since the original arcade and sega genesis ones so Im not sure what I would do with them but Im sure I could figure out something. This looks awesome though and would be fun too color flats Im not so sure thats always the least fun and one of the most time consuming parts of coloring for me.
If you had flats you were willing to post and share then I would love to give a shot at coloring the pic I think it would be a lot of fun, I could do flats too as well but if you have some already close to done it would make it a lot easier for sure.