So I have this tiefling barbarian, named Nehiri Tallstag. It's expected that she would have a few scars as a result. But see, she's also a soldier, a war veteran at age 24.

In the world of Unu-Nulo, there was a war between the mortal races and the monstrous races. The Tallstag family is a military family, and Nehiri's older brother Akmir, was the first of the siblings to enlist when the war broke out. Shortly before Nehiri came of age to join up, he was officially listed as Missing In Action. When she did join, Nehiri was catapulted up the chain of command, due in part to her family name, and was given a squadron to command. Their first mission was a simple recon commission, reclaiming a base for the mortal races that had apparently been cleared of monsters. In reality, it was an ambush. Nehiri froze up. Her soldiers were slaughtered and she panicked, unable to move or do anything to help. It wasn't until the monsters turned on her that she snapped. The rest of that night is black. Somehow she survived. Somehow she got out of that base alive and returned to her commanding officers. When filling out her report the next day, Nehiri took a breath and lied, saying that she did what she could to help her men, but they were outnumbered. It's a secret Nehiri is determined to take to her grave.

Or for, like, a shortened version, just listen to History Has It's Eyes on You from Hamilton.

Most of Nehiri's scars are generic battle scars, but there are three important ones. The first is the one on her cheek, which she received during her frenzied rage to survive that night. The second is a burn on her shoulder. Her younger brother, Stolazar, is a cleric who deals mostly in fire spells. I haven't decided yet on the circumstances in which he burned her but that one is definitely his fault. And finally is the sun-shaped scar on her forearm. Said younger brother is a cleric of a sun god named Apollion and, long story short, there have been some blood sacrifices to him and that is the scar that remains from the ritual. But it's fine, they're a neutral cult.