Video game characters face paint. Master Chief?

So I was thinking how I could get my own son into face painting more and the only thing that interests him (age 11) is video games at this time. I don't mean the mario brothers either but rather the Halo Xbox 360 games etc. So I was thinking about a Master Chief design but have no idea where to even start it as it is all angles and I suck at those. Now I need to get a game plan together before I propose this to my son as it is like pulling teeth to get him to let me paint him. He has to want something in return to get his permission usually. So my question to you guys... have you ever painted a more mature video game character? Any ideas of how to paint a master chief design? I dont need this to be a fast one... just a really cool one for him and his friends age group... any ideas where to start practicing??