Magnus reaches forward. He doesn't warn Lan Wangji about the side effects of his healing -- this is a tiny wound, and things this small usually don't trigger either the memory-viewing or the glow.

He touches Lan Wangji's finger and, with the slightest dab of his power, heals Lan Wangji's cut.

To his surprise, he does get the tiniest little flash of... something. Something big. Something definitely divine.