"We were fighting and you got faint, so we left," he answers. "I took you up here. You're safe." He thinks there's something odd that's gotten him paranoid, because he seems to have a lapse in memory.

He seems to be fine aside from that, but it's still worrisome.

Lan Wangji is worried, and going through the memory of their fight. He definitely hadn't intended to hit Wei Ying so hard...

"Did I do too much damage while you were in another form?"

Some of the forms weren't as strong as Wei Ying, after all.