Probably nothing. Alternian culture is a survival of the fittest one.

Land of Colours and Mayhem

They’re given it at a young age, presumably by the same drones that build their hive.

Rose in Act 5 Act 2

Jade in Act 6 Act 5 Act 1 - Act 6 Act 5 Intermission 5 (not including Act 6 Act 5 Act 2) 

Not Eridan, he did not go grimdark no matter how much you think he did. That color contrast on the one page is not indicative on grimdarkness, that’s not how grimdark works.

“After [The Signless’s] execution, the body was burned leaving only his irons. They cooled in the ash, as if his anger itself was subsiding, and his followers appropriated their shapes in defiance of the Highbloods. The symbols became the sign of the Signless, always shown as colorless as the cold iron, to conceal the stigma of his hue”

He works alongside Gamz to help LE so you can go ahead and put him in the villain category 

nope

Clocks are what decide if a God Tier’s death was Heroic or Just or neither, by destroying it with the JuJu breaker he made it so he could not get a heroic or just death making him effectively Immortal

You’re free to believe so