Season Rebirth first appeared in Diablo III right before Season 5. It allowed players to take any of their non-seasonal characters and put them into a brand new season.
You can rebirth up to three non-seasonal characters in one season. Previous to this, players had to create a new character each season.
Season Rebirth solves the problem of running out of character slots. I used Season Rebirth in Season 7 for the first time.
Usually, when a new Season starts, I roll a brand new character and start playing. This time, I decided to use Season Rebirth on the very first character I created on launch night of Diablo III. My Demon Hunter is named ThirtySeven. Her name was inspired by Error 37 that kept popping up as everyone tried to log in at the same time.
The first thing I needed to do was select ThirtySeven from my list of characters.
There she is, in mismatched gear that was probably obtained before the Reaper of Souls expansion came out. When you use Season Rebirth on a character, the armor, weapons, and jewelry she is currently wearing temporarily disappear. You can retrieve them from your in-game mail after the Season ends.
I’m not sure I care about the gear ThirtySeven is wearing. If I finish the Season Journey through Chapter IV, she will end up with an entire set (which will be much better than what she had before).
Next, you need to look at the bottom right hand corner of the screen. There are two options: “Rebirth” and “Delete”. Obviously, you are going to want to click the button that says “Rebirth”. As you can see, you start with a total of 3 rebirths each Season.
This scroll appears after you click the “Rebirth” button. It says:
Rebirth to Seasonal
You are about to Rebirth a Hero. This will remove all equipped and inventory items and mail those items to your non Seasonal state.
You will have 30 days to Claim your mail.
This Hero will then be reset to level 1 and converted into a Seasonal Hero.
With just a couple of clicks, ThirtySeven the Demon Hunter was ready to jump into Season 7 and start slaying demons.