Very reasonably priced as an ally for a "flex" investigator. For a deck where I expect to regularly need to attack 2 or more times per turn, I'd probably prefer an ally with a static boost such as Beat Cop or Lonnie Ritter or Logan Hastings, but if I'm just going to be occasionally chipping in single attacks to clean up weak enemies or take a piece out of a large enemy to make the primary fighter's life easier, being able to switch between +2 attack on the few fights and +2 towards investigating the rest of the time is quite appealing. Some investigators that might like this flexibility include Roland, Tommy, Joe, Marion, Skids, or Leo.

Note that it doesn't even have to boost your own test, you could use this to boost someone else's test. Could be great for a support character like Carson, Carolyn, or Vincent.

Also note that it just boosts "skill value." Saxon is happy to help your mystic investigate or fight with their spells. Good boy!