You and the Doctor have been travelling time and space for a while now and he’s always been able to protect you - to save you from harm and shield you away even as Daleks shot at you relentlessly.
But now? Now, you were hurt. Hurt by a species that even the Doctor hadn’t encountered before. Their power and strength was unknown, everything completely unknown yet he stood, in front of you, with confidence and a fierce glare that would make even Vashta Nerada quiver and run away.
“I gave you a chance to run and you didn’t. That was your first mistake…” He said, venom behind his words as he glared furiously to the creature in front of him, “But now you’ve hurt someone I like. I’m angry; that’s now!” He chuckled lowly, “I don’t know what I’m going to do now.”