Lind was covered in blood and filth. His once lithe body was now more heavily muscled but not to a massive extent. He had finally figured out what the Relic was for. It was not a survival trial, but a tempering crucible.
The entire Relic was designed to push a cultivator to the limits of their physical ability and then begin to temper it through battle. If Lind had been trained heavily in combat techniques, he would have been working against his already honed instincts but instead he was able to adapt and improve quickly.
His cultivation was incredibly solid and improved from high Stone Tier to the peak in the second week. His body began to absorb the force as he realized he could temper his body in the Relic. His cultivation was not geared towards body tempering but it could only help as he had not learned a technique yet.