I would advice against making an NPC solely for the purpose of solving PC's problems for them. It is fate so combat can be done pretty easily without the right skill set by stacking advantages. Making NPC do it all for us only makes combat scenes less meaningful as we can just 'get carried' through them which means less PC involvement and less responsibility. Or are you thinking of playing a PC yourself as well? Generally I think it's a very bad idea in Fate, but not against giving it a try either if you're confident you can do it.