Holy Light Repentance

The Paladin's Repentance dealt no damage but it could force the target to repent for the duration of one minute, in which the target would remain immobilized and their skills disabled. Should the target sustain any damage, the Repent status would automatically be dispelled. 

Cassio's Holy Light Repentance was different from the regular Repentance used by players. He was a Disciple of the Holy Light, his Repentance was infused with Holy Light Punishment, inflicting damage per second. Each damage was at 100+ and it doubled with every 10 damage inflicted.

"If Repentance supplemented with Holy Blessing was cast on a Holy Light devout believer, they'll recover HP but if this was cast on you, a sinner who desecrates the Holy Light, punishment will be bestowed upon you."

Cassio was gloating as he watched Li Yi's HP drop.