Klaus didn't even put in any effort to stop Reynolds from getting himself beat up by Grey.
Unlike when Grey sparred with Klaus, they didn't exchange any moves here. He directly transported Reynolds to another place.
A few minutes later, they returned. Reynolds was in a sorry state when they returned. Klaus was smart and told Grey not to use all his elements, Reynolds didn't think about that and straight up started fighting with Grey.
Grey didn't give him the chance to state any stipulations for their spar, and he beat the shit out of him.
"Did he use his new technique on you?" Klaus asked when he saw Rey's face.
Reynolds shook his head, but then he realized the meaning behind Klaus' words. Klaus sparred with Grey, and Grey used a new technique on him to defeat him. He wasn't as lucky as Klaus and was beaten blue and black. In fact, he tried running away, but Grey didn't give him the opportunity to do so.