Bad Luck Blade

Antimagic Susceptibility. The sword is incapacitated while in the area of an antimagic field. If targeted by dispel magic, the sword must succeed on a Constitution saving throw against the caster's spell save DC or fall unconscious for 1 minute.

False Appearance. While the sword remains motionless and isn't flying, it is indistinguishable from a normal sword.

Lucky. (7 per short or long Rest) The Bad Luck Blade has 7 luck points. Whenever is makes an attack roll, an ability check, or a saving throw, it can spend one luck point to roll an additional d20. It can choose to spend one of its luck points after it has rolled the die, but before the outcome is determined. It choose which of the d20s is used for the attack roll, ability check, or saving throw.

It can also spend one luck point when an attack roll is made against it. Roll a d20, and then choose whether the attack uses the attacker's roll or yours. If more than one creature spends a luck point to influence the outcome of a roll, the points cancel each other out; no additional dice are rolled.

Lucky Longsword +3. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 8 (1d8 + 4) magical slashing damage.