I don't think he's trying to break her morale. from my perspective it seems he was provoking her so she'd go all out so he could test the new power, while also showing her the limit of her own strength. He's being mighty shady about it though and I don't like that
it's been a while since I last read a manga that made me cringe so much. it's getting hard to read this with this mc but I'll soldier on since it's short and complete
I was enjoying this series and then they decided to through in the cheating. If it was an open harem i'd have been fine but now I've almost lost all interest smh. Guess I only have Gaishuu to continue filling the smut void now