You have a +2 bonus to attack and damage rolls made with this weapon. Any missile fired from this weapon when on the Elemental mode is considered magic even tho the weapon itself is not.

When fired both missiles fire from "The X" make two attack rolls. when loaded both "barrels" are reloaded. 

A runic inscription follows the length of this weapon, as a result of the magic any missile fired from "The X" can as a bonus action be modified with the following effects.

Grappling: A magic rope attaches to the end of the missile. The rope can extend up to 60 feet and stays for 5 minutes, two of these ropes can be attached simultaneously. if fired at a creature the missile damage is reduced by 1d6. 

Restraining: Bothe arrows fire at once with a net spread out between them, make a ranged attack roll for normal damage. if a creature of large or smaller size is hit with this attack it makes a dc 16 dexterity save or be restrained until an action is used to untangle the net. 

Elemental: make attack rolls as normal. on a hit roll a d6 to determine the kind of damage the attack does. (both arrows do the same type).

1. Poison damage
2. Acid damage
3. Psykick damage 
4. Lightning damage
5. Fire damage
6. Radiant Damage

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

Notes: Bonus: Magic, Damage, Combat, Ammunition, Heavy, Loading, Range, Two-Handed, Push