Katana of the Magus Slayer (5e Equipment)
From D&D Wiki
Weapon (longsword), legendary (requires attunement)
"This magic weapon was created from a supernatural alloy and imbued with anti-magic properties."
You gain a +1 bonus to attack and damage rolls made with this magic longsword. If you are not proficient with longswords, while you are attuned to this weapon it grants you proficiency.
Spell Negation: While holding this sword, to cast any spell you must make a DC 15 Wisdom or Intelligence saving throw (your choice) or the spell fails. When a spell fails in this way, your spell slots or charges used to cast it are not spent. You also have disadvantage on your spell attack rolls and creatures have advantage on their saving throws from spells you cast.
Spell Absorption: While holding this sword, you have advantage on saving throws from magic.
Revenge of the Mage Slayer: This weapon is cursed. Attuning to it curses you until you are targeted by the remove curse spell or similar magic. Releasing the weapon fails to end the curse on you. While you are under the curse of the Magus Slayer, you find conversing with any known mage, or magically-related person(s) fills you with rage. You have disadvantage on Charisma checks while talking to any mage, or magically related person(s).