Personally I feel like this story didn't even need Subaru. If he doesn't even have his canon power then this is assuming Satella does not love him, if he doesn't love him why is he even summoned? I am not saying Subaru needs more powers. But more so the fact that if the MC is just taking Subaru place with Emilia and the others then Subaru doesn't even need to exist here. You could have just not had him be summoned and overall not a lot would have changed.