Sacrificial Knife

Weapon (dagger), rarity varies (requires attunement)

Runes dance along the blade of this keen knife.

Sacrificial Knife (Common). While attuned to it, you can use this magic, rune-inscribed dagger as a spellcasting focus.

Ceremonial Sacrificial Knife (Uncommon). More powerful versions of this blade also exist. While holding the greater version of this dagger, you can use it to perform a sacrificial ritual during a short rest. If you sacrifice a Tiny or Small creature, you regain one expended 1st-level spell slot. If you sacrifice a Medium or larger creature, you regain one expended 2nd-level spell slot.