Astute Weapon Nodule

This crystalline device must be attached to a bladed weapon to function. Applying the nodule takes an action. In order to become properly attuned, the device requires the user to engage it in a conversation in which the wielder of the bladed weapon introduces themselves and gives the weapon a unique name. Once attached to a bladed weapon, the nodule can not be removed by any means. 

The affected weapon then becomes a sentient item with a personality and outlook similar to yours. It can speak, and understand one language in common with you, has hearing out to 60 feet, and an alignment that is either the same or within one step of yours. It will not permit you to use it in a fashion that is out of sync with its alignment. For example, if you are a Lawful Good character, but attempt to use the weapon to murder an innocent civilian, the weapon will resist thus giving you disadvantage on the attack rolls. 

Its Intelligence, Wisdom, and Charisma are 10 (+0).

Once per day it can be activated by speaking the weapon's name in order to engage one opponent by reading the opponent's weaknesses and identifying their vulnerabilities, thus giving you advantage on attack rolls against that one opponent for 1 minute. Once this ability is used, it can't be used again until you take a long rest.

Notes: A conversation in which you introduce yourself and give the weapon a unique name.