Characters can be First Reborn when they reach Level 120 (or 110 Water Taoist)

What you need:

One of every normal gem but Tortoise.

CleanWater.

Gems can be obtained either by mining/paying the auto miner or occasionally dropped by all enemies.
Also don’t forget that you can decompose Refined Gems into normals in market if you need to!

CleanWater can be obtained from WaterLords deep in Adventure Zone.

Get to Adventure Zone from Desert City.

From Serpents/Basilisks its top right, top left, top left.

Once you have the Gems and Clean Water find Celestine in TC. (Northern Edge)

Now that you have a Celestial Stone you have everything you need to get Reborn!

To finish the process you’ll need to walk the Sky Path and find Eternity.

This map is at the top left corner of Ape Mountain.

Select the class you want to Reborn into and the Gem you want and Boom. Reborn back to level 15.

What you’ll get:

You’ll get 10 extra Attribute Points for each level past 120.

Your skills will be reset back to elementary and you will obtain skills based on your rebirth combo.

Trojan Reborn into-
Trojan = CruelShade
Archer = Cyclone, SpiritHealing, Robot
Warrior = Cyclone, SpiritHealing, Robot
Fire Tao = Cyclone, SpiritHealing, Robot
Water Tao =Cyclone, SpiritHealing, Robot

Archer Reborn into-
Anything- NOTHING

Warrior Reborn into-
Trojan = Roar, FlyingMoon
Archer = Shield
Warrior = Reflect
Fire Tao = Shield, Roar
Water Tao = Shield, Roar

Fire Tao Reborn into-
Trojan = Thunder, Fire, Cure, Meditation
Archer = Thunder, Fire, Cure, Meditation
Warrior = Thunder, Fire, Cure, Meditation
Fire Tao = Dodge
Water Tao = Fire Circle

Water Tao Reborn into-
Trojan = Thunder, Cure, Stigma, MagicShield, Meditation
Archer = Thunder, Cure, Stigma, MagicShield, Meditation
Warrior = Thunder, Cure, Stigma, MagicShield, Meditation
Fire Tao = XPRevive, AdvancedCure, HealingRain
Water Tao = Pervade