Regeneration

Description
At the cost of mana, heal, regenerate or restore your physical conditions.

[Low Rank Regeneration Lv1 (Active)]

[Damage is healed through magic. Regeneration speed and effectiveness increases.]

[The Low Rank Regeneration skill has become Lv10 and has evolved into the intermediate level. Severe injuries and status ailments can be restored.]

[The Intermediate Regeneration skill has become Lv10 and has evolved to the high rank level! Health and Magic have increased by 20. In the case of a mana based attack, you can collect a portion of the mana and activate Regeneration.]

~Chapter 21
Somewhere just before or during his level up to Lv3 it developed from beginner rank into Low rank.

Chapter 82
Developed from Low rank into Intermediate

Chapter 141
Developed from Intermediate into High Rank