This Longbow deals standard damage at 1d8 piercing plus standard modifiers, but if the wielder decides to sacrifice an amount of life to the bow, the bow will deliver twice that amount on a hit. The sacrifice must be made prior to making the attack, and if the attack misses the sacrifice is lost.
Enchantment Damage (X = Sacrificed Healthpoints): 2X additional force damage
Critical hits do not alter this damage.
Proficiency with a Longbow allows you to add your proficiency bonus to the attack roll for any attack you make with it.
This weapon has the following mastery property. To use this property, you must have a feature that lets you use it.
Slow. If you hit a creature with this weapon and deal damage to it, you can reduce its Speed by 10 feet until the start of your next turn. If the creature is hit more than once by weapons that have this property, the Speed reduction doesn’t exceed 10 feet.
Notes: anyone not Lawful Good., Damage, Combat, enchantment, Ammunition, Heavy, Range, Two-Handed, Slow
I'd appreciate any feedback that I can get.
Put a cap on the sacrifice HP.
Something like 1 hit die per proficiency bonus. So a barbarian at 1st level could spend 2d12 because his/her proficiency bonus is +2. This would net a max at level 20 of 6 hit die, or 6d12 for the example barbarian. The hit die can be spent all at once or in any combination they like not to exceed the proficiency bonus.
Any healing of this damage type is healed at half the rate of other wounds. So, halve the healing from cure wounds and potions for any of the sacrifice damage.
Reset the ability after a long rest.