Source: Eberron - Rising from the Last War

Prerequisite: Elf

You are descended from a master of the double-bladed scimitar, and some of that mastery has passed on to you. You gain the following benefits:

• Increase your Dexterity or Strength score by 1, to a maximum of 20.
• While you are holding a double-bladed scimitar with two hands, you gain a +1 bonus to Armor Class.
• A double-bladed scimitar has the finesse property when you wield it.