Oh man having a vanilla mortal would be really cool actually... Like I'm wagering a large part of this would take place in the Europe given that was our big bad's stomping ground especially after WW2. 

like...this area and time period a really cool human role would be a cold war spy, who following rumors of mysterious activities (( assuming some new weapon or tactic of his rival nation )) and stumbles into the still raging supernatural conflict happening in the shadows of the mortal world.

If somebody wants to use this idea go for it, but if nobody wants this idea I'll scrap my warden and play this role :D