[Why does he have to explain this? Why does he have to talk through this again.]

When Satan broke the koma sword, it broke the seal on your powers, and your demon half. [He's had to put this together himself, with what little he knows. He wants to scream. He wants to rip his own eye out. That wasn't supposed to happen, not to Rin.]

It's something you could, and did, recover from.