Max felt an energy coursing through his skins into the veins and then into his body. It wasn't as strong as the previous times. But Max could still clearly feel that it was the same Flow energy that he has been practicing with the help of the system so far.
Max kept circulating the energy and slowly absorbing it through his body. But in all this process, Max didn't feel any reaction even when he tried to bring the Flow energy around his hands trying to stimulate a response both from the beast core as well as his own crystallized core. It clearly meant that the Ancient Manual was not meant for refining the core like Mana Arts.
And from the way it worked, Max could feel that this Ancient Manual was meant for strengthening the body.
After 30 minutes, Max felt his mental energy being drained as sweat dripped down his face. This process really required a high level of concentration.