Your CON ability score increases by 2 and one other ability score increases by 1.

Sentient weapons do not age and can last for an eternity if not destroyed.

Because of the many forms a sentient weapon can take, there is a pretty wide range of heights they can be, usually between 5 ft and 6.5 ft. Regardless of your position in that range, your size is Medium.

You can speak, read, and write Common and one extra language of your choice. Sentient weapons typically learn a language their creator knows. 

Using your bonus action, you are able to transform into your weapon form for up to 2 hours. While transformed, you gain a flying speed of 20 feet which replaces your walking speed; you cannot fly above 5 feet off the ground, and you are unable to cast spells. You also gain resistance to bludgeoning, piercing and slashing damage. When making a melee attack, use the weapon type chosen for dice rolls; use your CON modifiers for attack rolls and damage but do not add your proficiency bonus to attack rolls. Alternatively, you can have an ally wield you as a weapon, in which case you count as a magical weapon of the chosen type with a bonus equivalent to your proficiency bonus. Any items or clothing on your character's person are transformed with your characters, but living beings on your person are not transformed.

You can use this trait a number of times equal to your proficiency bonus per long rest.

While in humanoid form, if you hit 0 hit points and fail your death saving rolls, you do not die. Instead, you instantly transform into your weapon form without the ability to act autonomously. In this dormant state, you no longer count as a magical weapon if wielded by an ally. While you cannot interact with the world, you are still able to see and hear what goes on around you. You can be restored in the same ways that other characters would be revived.

You have blindsight up to 10 ft.