Voxin's Impenetrable Sanctum

You make an area within range magically secure. The area is a cube that can be as small as 5 feet to as large as 250 feet on each side. The spell lasts for the duration or until you use an action to dismiss it.

When you cast the spell, you choose a number of creatures or creature types. Those creatures can enter the area freely. Creatures not specified during the casting cannot enter the area.

You cannot overlap the spell on an existing instance of this spell. Instead of creating a new area, if you were the original caster, you may modify the creatures or creature types that are allowed.

You can cast this spell again while it is active to maintain the sanctum’s existence for another 24 hours. When you do so, you may change the creatures or creature types that are allowed in the area.  You can create a permanent sanctum by casting this spell in the same location and with the same configuration every day for 30 days.