
Arrow, very rare
This magic arrow is infused with Aether, an alchemical composite made with pure arcane energy. Aether is a primordial form of energy ancient and powerful. It can only be found in places blessed by the God of Magic or in settings exposed to such powerful magic effects it affected the very environment. Alchemists can attempt to prepare an imitation of Aether they call Eather. If you are proficient with Alchemist Tools, you can spend ten days of work and 500GP worth of materials to craft one bottle of Eather.
When you cast a spell of 4th Level or lower while holding this magic weapon you can choose to store it within the arrow. The spell must target a single creature or an area. The spell being stored has no immediate effect when cast in this way.
When this arrow hits a target, the stored spell is cast. If the spell has a target, it targets the creature that was hit by the attack. If the spell affects an area, the area is centered on that creature. If the spell summons Hostile Creatures or creates harmful objects or traps, they appear as close as possible to the target. If the spell requires an attack roll against the target it automatically succeeds. If the spell requires a saving throw to avoid its effects the target of the arrow makes the test with disadvantage. If the spell requires concentration, it lasts until the end of its full duration.
When the spell stored in the arrow is cast, the Aether in it dissipates and it becomes a nonmagical arrow. You can expend an action to recharge the arrow with Aether, or a bottle of Eather. Once recharged, you can infuse the arrow with a new spell.