Well now, does he not see the parallels between him and the talented people the slaughter god finds?
Perhaps he is behind the research on the devours? Maybe he has incomplete space knowledge? Also his 'eye' for people's talent could be that he has an ability to identify their ESPER powers. Much like how Bloed and his SSS rank Molecular Disintegration and his C rank Enhanced Brain Capacity which would be hard to identify let alone train with the knowledge that 'that' planet had, or he is an interspace person and is using their planet as a Lab trying to use Devourers and then exploit them on an interspatial war or maybe in trying to learn to use them to kill themselves?
Anyway with Bloed's big brain he should be able to see this too. After all his situation is very similar.
So the God of Slaughter is the same person that is researching the devours and commanding Returning Dusk. To bad for the MC he is already marked as a valuable sacrifice.
Orthanos