Death Eaters
Christian was moderately injured in his first duel with Sturgis. Stu blasted away a wall behind Christian, and he took several airborn bricks to the head and back, giving him a lovely concussion, some scrapes and bruises, and one hell of a back injury. His duel with Remus was shorter-lived, but cost him pretty much the last shred of energy he had left.
After the battle, he would have gone to Lestrange Manor to get whatever needed to be healed healed, and then back home, where he probably passed out and woke up the next morning with a hell of a headache and a wonderful assortment of bruises.