lame™

Asked about the backstory of the fight Nyx and Eclipse had,,

Here goes.

Eclipse and Nyx were not best of friends back then. They were actually enemies. They despised each other. So one they Eclipse accidently bumps into Nyx in front of Nyx's so called 'good friends' and Nyx teases her. Eclipse however, gives a good comeback, and Nyx's friends start to laugh at her, calling Nyx weak.

Nyx upon seeing this, got angry, and pounced onto Eclipse, cuffing her ear. Eclipse retaliates, giving a deep cut on Nyx's lower left cheek (thus the bandage)

Before one of Nyx's friends grabbed her by the scruff, she managed to give Eclipse another critical slash on the eye, causing her to lose her sight unintentionally.

How did they become friends?

After the fight, Nyx got kicked out of her 'friend gang'. She realised what she did to Eclipse, and checked on her sometimes after school, since they live across the street.

Soon she realises that Eclipse was no threat and Eclipse lives alone since her parents died. So was Nyx's parents, so they soon started to talk to each other, realizing each other's similarities.

From that day onwards, they helped each other through thick and thin.