Hello! This artifact was invented by a friend of mine, who gave it to my GM, who gave it to our party, and I ended up using it (as a barbarian, because having a lot of hit points helps with it).
However, because of the way it was created mostly ad-hoc, there are some issues with its functionality and I'm not sure about its balance. This form I wrote up, and I already modified the way the HP drain works a little - we'd been doing it basically that the damage is gradual but the GM is in charge of your HP while using it. Anyway, what do you all think? I included some matters for discussion at the bottom.
Blood Bow
Aura: Strong Necromancy, Transmutation, and Evocation CL: 20th Slot: None Weight: 3 Lbs
The Blood Bow is a magical Adaptive Composite Longbow. When drawn with an arrow nocked, it has no other special properties, but when the string is drawn without an arrow, the grip of the bow bites into the user's hand and an arrow is formed seemingly from the wielder's blood. Arrows formed in this way are by default +1 Arrows, but as a free action, the wielder can cause the arrows to increase in enhancement bonus up to +5, and can cause the arrows formed to be blunt arrows. The wielder can also add any ammunition-effecting ranged weapon special properties (See below or GM's discretion) to the arrows, to a maximum of +10 combined bonus and ability cost. However, the blood drained to create the arrows takes a toll - the wielder takes 1 HP of damage for every point of bonus and ability cost on each arrow fired. This damage is not immediately noticeable (and should be tracked by the GM), and is dealt all at once when the user lets go of the bow or at the end of combat. The bow has had many wielders prove victorious in battle, only to die afterwards from the weapon's damaging effect. Its longest-term successful wielder was a Paladin, who mitigated the effect by laying hands on himself.
(Ammunition ablities: Flaming, Flaming Burst, Shocking, Shocking Burst, Frost, Icy Burst, Corrosive, Corrosive Burst, Igniting, Anarchic, Axiomatic, Holy, Unholy, Bane, Merciful(?), Brilliant Energy, Conductive, Cruel(?), Cunning, Lesser Designating, Greater Designating, Ghost Touch, Limning, Seeking, Phase Locking, Planar, Thundering, Compassionate(?))
Matters for consideration: Should there be a Heal check to notice the effects of the damage sooner, and what DC? Should the damage be healable before the bow is released, either by being dealt gradually or by having healing spells able to count against it? CON damage instead of HP damage (as blood loss often is)? Die roll damage per modifier instead of flat 1 HP? If so, d2? d3? d4? d6? Should Cruel, Merciful, and/or Compassionate be allowed as enchantments (Merciful and Compassionate might not fit the flavor, and Cruel, since it gives you temp HP on kills, could be a little cheesy)? Should applying/changing the bonuses be a free action, or a swift (Strongly inclined free, since the cost is per arrow). Should assigning special abilities rather than just flat enhancements require a Spellcraft or Knowledge (Arcana) check, at least for the first time for each ability? (the bow is capable of forming the effects, but the check would be for the user to basically be able to understand and communicate what they want the bow to do.) If so, what DC?
Just my two cents, but as a GM I would replace the effect with a randomly determined 1-10 or 1-20 roll each arrow fired with the option for the player to enhance the chances of a higher roll by sacraficing HP. Still apply the affect after shot has been fired and apply all dmg at the end of combat....would be a high risk/high reward weapon.
It is an artifact weapon afterall.
D10
1 normal arrow -1 hp
2 +1 arrpw -2 hp
3 +2 arrow -3 hp
4 +2 arrrow +1 effect -4hp
5 +3 arrow +1 effect -5 hp
6 +3 arrow +2 effect -6
7 +4 arrow +2 effect -8
8 +4 arrow +3 effect -10
9 +5 arrow +3 effect -12
10 +5 arrow +4 effect -14
D20
1-3 (Normal Arrow -1hp)
4-5 (+1 arrow -2hp)
6-10 (+2 arrow -3hp)
....etc