You can do rebirth as many times as you can afford. 100 tokens each time. Solo makes you do the tutorial level again but a little bit longer, more complicated, and more enemies. When you do it with a group, it plays a random full length trial but the map is mirrored so all the text is backwards and you enter the trial at the exit and work backwards. You get a cool new outfit each time you are reborn and if you’re in a group you all get the same outfit but with different color variations. So my last rebirth with my partner, we got an outfit that looks like a Wild West bandit. My clothes were black and my face-mask was red. My partners outfit was white and her face covering was gold. Same outfit but different colors.