You have a +3 bonus to attack and damage rolls made with this magic weapon. 

This bow is made from the spine of a wyvern, and its black string is made from the treated muscle of Ikvara, the Dual Terror. The bow pulses between being warm and cold.

You gain a +3 bonus to attack and damage rolls made with this weapon.

While attuned to wyvernspine you gain resistance to fire and cold damage, you can read and write draconic, and you have advantage on Charisma checks while interracting with dragons, as well as Intelligence checks regarding information on dragons. You also gain advantage on saving throws against the breath weapon attacks of dragons and immunity to being frightened of dragons.

This bow does not have disadvantage on ranged attack rolls against prone targets.

The bow has 7 charges, which all return each day at midnight. You may use these charges by speaking draconic, and doing so activates the following traits:

Tyrants Agony: After you hit an attack, you whisper a word in draconic that evokes sharp pain in its new wound. Expend 1 charge and it must make a DC 19 Constitution saving throw or fall prone from the pain. If the target is a dragon it has disadvantage on its save, and it also takes an additional 3d12 piercing damage on a failed save, or half on a success.

Twinned Arrow: When you make a ranged attack roll you may expend 2 charges to have the bow duplicate the fired arrow, making a seperate attack roll for the new arrow. The first arrow you fire deals an additional 1d8 fire damage and the second arrow you fire deals an additional 1d8 cold damage. You may only do this once per non-duplicated arrow you shoot. If the target is a dragon, this trait costs 1 charge instead.
[11:45 PM]
Wyvernsting: After hitting an attack, you may expend 1 charge, magically empowering the arrow with a vile poison. The target must make a DC 19 Constitution saving throw, or take an additional 3d6 poison damage. If the target is a dragon, it has disadvantage on the save, and it also becomes poisoned on a failure. While poisoned this way its movement speed is halved (no matter what kind of movement it is).

Scaleshot: As a bonus action you may expend 1 charges to gain advantage on all attack rolls against all dragons for the next minute.

Breath of Iknaji: As an action, you may expend 3 charges to exhale fiery breath in a 60 foot cone originating from you. Creatures in the cone must make a DC 19 Dexterity saving throw, taking 14d6 fire damage on a failed save, or half as much damage on a successful one.

Breath of Anvara: As an action, you may expend 3 charges to fire an arrow of ice. Creatures in a 90-foot line that is ten feet wide originating from you must make a DC 19 Constitution throw, taking 11d8 cold damage on a failed save, or half as damage on a successful one. You make one longbow attack at advantage on a creature within the line, but you must choose this target before the the damage from the other effects is dealt, as the cold stream follows the arrow.

If a dragon is the target of either Breath attack, you may use a bonus action to activate the Breath instead of an action.

Proficiency with a Longbow allows you to add your proficiency bonus to the attack roll for any attack you make with it.

Notes: Damage: Piercing, Prone, Longbow, legendary (requires attunement), Damage, Combat, Ammunition, Heavy, Range, Two-Handed, Slow