The previous three skill books were all third-order skills. Chu You knew that in the third stage of the combo technique, when it falls into an Area Fluctuation, there was a 50% chance of initiating a Shock Wave. If it doesn't, then it would only be a two-strike combo. But regardless, he finally assembled a full-phase combo technique.
All warriors could learn the skill of Blood Qi Recovery, it was a systematic skill. Although these are very expensive, many people need them. This particular skill could bring 4200 HP recovery to a warrior. Warriors that can take hits and deal damage need such skill enhancement.