This dagger's crossguard is in the shape of an infinity symbol, the handle bares metallic thorny protrusions puncturing it's old worn out leather strapping. The blade is a twisted triple helix with the tip  pointed into a 3 pronged arrow.

The first time you attack with the dagger on each turn, you are dealt 1d4 damage, as the thorns of the handle cut into your skin.

When you hit with an attack using this magic dagger and reduce the target to 0 hit points, the target's soul is consumed by the eternal abyss and destroyed utterly.

Tear Reality.  you can cast teleportation circle once per day using the blade itself as a focus to carve the circle into the ground. If this ability is used on a plane of existence outside of the abyss, it can only create a portal to a random location in the abyss(this does not require another teleportation circle as the destination).

You have a +1 bonus to attack and damage rolls made with this magic weapon

Proficiency with a Dagger allows you to add your proficiency bonus to the attack roll for any attack you make with it.

Notes: Bonus: Magic, Damage, Combat, Finesse, Light, Thrown, Nick