The sensation of such strong emotions washing up against his own like sea on the shore line would be a little discomforting, if he allowed it to be. As it is, Wangji is just glad he can help. The draining sensation is noticeable, and makes him feel progressively more tired and wan. He doesn't regret it, his offer to help was sincere and this was progress.

"You protect this place? Alone?" That seems like a large task. The latter half seems more important;
"Unstable energy? Does it feel like my energy or just foreign?" If the storm came from else where, as they did, perhaps they would have to send it back.