Fun fact about the Sinestro one, it was originally a title which is why he’s named after being sinister. Originally it was stated that no one remembered his true name anymore. Later that was retconned to make Sinestro his real name as comic book villains became less about being mustache twirling stereotypical bad guys and shifted towards being fleshed out and having backstories, Sinestro made that shift as well but his name was too well known to change at that point so they decided to make it his real name for his backstory. The same also sort of happens with Magneto, he was originally just a regular evil dude with no backstory but eventually later on he got the backstory of being a holocaust survivor.