not sure but i doubt its summoners shard. when chapter two comes out its likely that us summoning scribbles will be a key part of the storyline. if we summon him in chapter one (which will happen if we join summoners shard) chapter two would make no sense for the route with Therium/summoners route. tbf its common sense and im suprised a lot of people took so long to understand that, but then again i've gone into a lot of deep thinking about this subject.