New to Chapter 2 is a mechanic that allows you to resurrect fallen teammates that were exiled earlier in the match. Here's how it works:
Once you enter a new Spellstorm circle, you'll have the opportunity to resurrect an exiled teammate. To do this, simply hold the "use" button/key (while not targeting a usable object) for 12 seconds.
After this process is completed, exiled teammates will begin a drop process from the sky above you. Resurrected teammates will respawn with only their chosen Class gauntlet (common) and will retain any Talent level-ups they earned before being exiled.
Note: this process can only be completed once per Spellstorm ring, but can be done multiple times per match.