Mobile Character Directional Light.

So all I’m trying to do is simply get a directional light to shade my character light when he’s in “the light” as in the first pic and shade him to dark when he’s “in the dark” like in the second pic. Not trying to add fancy shadows, I just want the character to be shaded according to world position. I have exponential fog and a skylight, but I’m starting to realized the problems are probably with the directional light. I’m aware of setting it to movable, but that sort of works and it’s 10x more expensive running it on mobile. Anyone got any ideas. BTW the goal is to get it to work on mobile.