Couatl Herald's Fang
This vibrant blade carries with it some of the properties of the couatl who either forged it or the couatl whose scales it was crafted from. You gain a +1 bonus to attack and damage rolls made with this magic weapon. In addition, when you roll a 20 on an attack roll made with this weapon, the target takes an extra 2d6 poison damage and must make a DC 15 Constitution saving throw. On a failure, the target is incapacitated and has a speed of 0 until it takes any damage or someone else uses an action to shake the target out of its stupor.
Flight of the Couatls. While you’re attuned to 3 items with this property, you gain a flying speed of 30 feet. If you already have a flying speed, your flying speed increases by 30 feet instead.
But the invaders were relentless. Only the warriors chosen by the city's protectors had the strength to subdue them. And even then, more would come.