บท 31: Chapter 31 Change In Talent! 

The effect of {Undead Revival} was straightforward.

It revived a corpse as an undead. 

However, reviving a corpse could fail in three scenarios.

First was the mastery of the skill.

The success rate of {Undead Revival} depended heavily on its mastery level.

{Basic Mastery} was 20% success rate.

{Intermediate Mastery} was 50% success rate.

{Advanced Mastery} was 80% success rate.

{Perfect Mastery} rarely fails.

At {Perfect Mastery}, effects of a skill were said to evolve, but Michael was far from that level. 

With his {Intermediate Mastery}, Michael's chances of success were only 50%.

Second was the strength difference.

Reviving a corpse also depended on the difference in strength between the necromancer and the corpse.