My theory is that Gojo negative expression in this chapter is less about his relationship with Marin and more about his competence as an artisan. I would expect that an artisan would want their pieces to be appreciated by it's own merit and not through the endorsement of others. In other words...
MC is an idiot. It's as if he expects his team mates to read his mind and figure out that it was his power that was buffing them. What's worse is that he turned himself into the lynchpin of the team without letting the rest know.
Even if his party were good people, they would have still let...