Rod of Absorption

While holding this rod, when you are the only target of a spell you can use your reaction to absorb it as it is being cast. An absorbed spell has no effect and its energy is stored within the rod. The spell’s energy equals the spell levels used to cast it. The rod can store up to 50 spell levels worth of energy over the course of its existence. The rod cannot hold more than 50 spell levels worth of energy. If the rod does not have the space to store a spell and you try to absorb it, the rod has no effect.

After attuning to the rod you know how much energy it currently contains and how much it has held over the course of its existence. A spellcaster can expend the energy in the rod and convert it to spell slots—for example, you can expend 3 spell levels of energy from the rod to cast a 3rd-level spell, even if you no longer have the spell slots to cast it. The spell must be a spell you know or have prepared, at a level you can cast it, and no higher than 5th-level.

When found the rod contains 1d10 spell levels. A rod that can no longer store energy and no longer has any energy remaining within it loses its magical properties.