"Thank you, Dark souls" is a popular phrase invented and most famously used by the well-known youtuber "videogamedunkey".
It's often used in bullshit situations, or otherwise unfair scenarios.

n. The birth name of somebody who has changed their name. Most commonly attributed to trans people, but can be attributed to any person who has changed their name. (sometimes written as two words: dead name)

v. 1. To call somebody by their deadname.
v. 2. To out somebody's deadname to the public.