New Magic Weapon Idea

[HopefulDMing]

Level them with players. Have them be sentient (or at least somewhat aware) and withhold their true powers until the players prove themselves worthy.

That's a good idea, but what should I do at lower levels? They should still be some of the better items they have if they have them, and I would like them to have some more utility outside of combat and plot. Maybe give small boosts or immunities?