her backstory according to a /co/ post, no sources since the episode hasn't been leaked online (yet) but it sounds bad enough to be believable
"She wanted powers, but the Professor warned her not to. When he finally gave in and started the process he miscalculated something and his lab assistant lover, who Bliss called mom, was killed in the blast. Bliss lived on account of receiving the power prior to the explosion, but the Professor was too angry at her for leading them into this before he could concoct Chemical X which would ensure the process would go smoothly. So after a big argument Bliss leaves to grow stronger"