Eiren hails from The ‘Jewel Mountain': the most prominent place in the Continent that produces gems. The dwarven race extracts gems from there, making fortunes. Eiren is the daughter of the King of the Jewel Mountain and the most prominent lady of the Continent. Increasing the wealth is the pride of Eiren’s clan and she’s famous for her outstanding business acumen and negotiation skills.
She’s the cousin of Ymir from the Steel Mountain. And now, seeking profit in the Continent shaken by the fight between the Rebel Army and the Queen’s Army, she has joined Ymir in the fight.
Like Ymir, Eiren's specialty is using a gigantic hammer that mismatches with her body build. It is still unknown as to how she is able to wield the weapon.