Avrus' Archway of Axes

You set a trap against unwanted intrusion. Choose a door, a hallway, or an area within range that is no larger than a 20-foot long cube. Until the spell ends, a set of 4 ethereal swinging axes remains active. When you cast the spell, you can designate creatures that can pass through the axes. If the trap is set off, a mental alarm alerts you with a ping in your mind if you are within 1 mile of the trapped area. This ping awakens you if you are sleeping.

When a creature that you did not designate passes through the axes they must make a Dexeterity Saving Throw. On a failure, the creature suffers 4d4 slashing damage and half as much on a success.