How in the world did someone gain reflexive reincarnation anyhow?
STEPHEN HAWKING. Yes, all caps are necessary.
For the long version, during the tail end of the assault mission, they attempted to kill a strong amp user. During this, a massive explosion occurred and two things of import happened.
1) STEPHEN HAWKING rolled extremely well on his END roll as a fresh character. This resulted in him surviving something that he honestly had no right surviving. In the flavor text describing this, PW said that STEPHEN HAWKING just stood there, in absolutely no cover, and all the debris and flames flew past him without doing any damage. Someone else actually used STEPHEN HAWKING as cover and *also* took no damage. This essentially established STEPHEN HAWKING as, (somewhat) appropriately, a walking quantum mechanical anomaly.
2) Grate, the child character GWG made that had been the center of some interesting roleplay with the veterans, was crushed completely by a falling boulder. This made everyone sad. Because the feels.
So after this event, people lit on trying to leverage STEPHEN HAWKING's unexplored control of some bizarre understanding of quantum mechanics to attempt to revive Grate. After all, no one has observed him being dead yet! So quantum mechanics (or the bizarre variant that the entity known as STEPHEN HAWKING uses) clearly says that we do not yet know whether he is alive or dead.
PW, being a lover of unintended consequences, gave us the okay, and so STEPHEN HAWKING acted as The Observer as the rest of the team lifted the rock... and rolled a 6.
And so was born Grate Mk2, standing over the greasy smear of Grate Mk1.
Of course, someone immediately shot him, and so Grate Mk3 popped into existence as well over the corpse of Grate Mk2.
If I remember correctly, we are now up to Grate Mk5. At least, as judging from the year long time-skip, he may have died a few more times during that, since it is mentioned that he discovered something about the effect. Grate Mk3 ate a manipulator battery and became an overload, and Grate Mk4 got chopped into bits by a reactor cooling fan.