Blade of the Patient Master (5e Equipment)
From D&D Wiki
Weapon (any sword), rare (requires attunement)
The handle and scabbard of this masterfully crafted blade are made from spotless ivory and feature a number of gold ornaments and engravings. Its blade is sealed in its scabbard with 3 knotted silver cords.
After you roll initiative this blade unties one of its knots for every action you spend without attacking or directly damaging a foe with a spell or other effect. When its knot is untied the corresponding cord dissolves and empowers the blade. If you draw the sword or use your action to attack or damage a foe all remaining cords instantly tear and crumble to dust, without empowering the blade. All cords reappear after combat is resolved and the blade is returned to its scabbard.
These are the benefits of the blade as well as how each untied knot empowers it.
Blade: When rolling initiative you may add one of your blade's damage die to the result. In all other regards the blade counts as a non-magical weapon, unless one or more of its knots are untied.
1 Knot: Until sheathed the blade becomes a +1 weapon. On the turn the blade is drawn an additional damage die is added to the blade's damage.
2 Knots: Until sheathed the blade becomes a +2 weapon and scores critical hit on a 19-20. On the turn the blade is drawn two additional damage die are added to the blade's damage.
3 Knots: Until sheathed the blade becomes a +3 weapon and scores critical hit on a 18-20. On the turn the blade is drawn three additional damage die are added to the blade's damage.