From now on, unlocking the next level requires that we roll back to level 10 each time we hit our max level. This cycle is called Reincarnation and looks like this: level 70 > level 10 > 71 > 10 > 72 > 10 > 73 > 10 > 74 > 10 > 75.

This cycle needs to be done individually for each class and we can double-check our current level cap in the status's window, under Potential Development (ctrl+A, attributes tab)

Updated March 11, 2020

Once we have 250,000 gold and are level 70 with our exp capped at 100%, we can head to Eversun City and speak with the Reincarnation Instructor, inside the dojo, to receive a free reincarnation stone and perform our very first rebirth. The following rebirths work the same way, however we will need to fetch our own reincarnation stone this time.

Get reincarnation stone...

1. With the use of 200 dreamstone essence and a dim reincarnation stone, a reincarnation stone can be crafted. If we have dreamstone essence recipe, one essence can be crafted with 10 dreamstones.
   
2. While chatting with Trader Girl in Eversun City, we can trade Daily Event Scrolls or Mission Certificates for both dim and not-dim reincarnation stones -- [read more]
   
3. The cash shop

An alluring benefit from reincarnation is that we gain extra skill points and attribute points -- +1 attribute point for every 5 levels gained and +10 skill points. Do note that the skill points aren't automatically gained. The game simply grants us the privilege to use more job springs, which results in +10 skill points if we use it. Job springs are available in the cash shop.

Exp credit card
To further increase our skill points, we can record our progress onto an exp credit card. Once we have 3 full cards, it can be exchanged for an Occupational Spring Water which grants us 1 skill point. Using the exp credit card requires our job to be capped with 100% exp and filling up the card will roll us back to 0%.

At level 70, we are allowed to trade in 1 full card and this number increases by one for each level until level 75 -- for a total of 21 full cards. One occupational spring water costs 3 full cards, meaning that we'll receive a total of 7 spring waters, each granting +1 skill point. Herein, by level 75, we will have +7 skill points. On the other hand, Sorcerer class can redeem double the amount of cards -- for a whooping +14 skill points!

Beast Mode is automatically unlocked after our first Rebirth. From now on, there is a chance for us to bypass death and transform into a powerful beast instead of dying! This phenomenon can occur only once per day and must be on a class which hath undergone at least one rebirth...

Cannot transform if...

• We died on a non-reincarnated class
  
• We died while riding a pet or a transformation box, scroll or pill was in effect

In the event that Scapegoat Dolls are in our inventory, they'll be used first. Once we run out, then Beast Mode may activate.

Each new rebirth unlocks a new beast appearance...

• Original pictures from wiki[domo.fandom.com], edited by me
  
• Rebirth info from wiki[domo.fandom.com], and in-game community