Lionni's Divine Shield

Brainchild of Determined heroes Raelyn Lionni and Alastaire Breowan, Lionni's divine shield was an 8th-level abjuration spell famously used as a defense against Vecna's Null in the Ultima War and into the Dark Age. It amplified and modified the effects of Leomund's tiny hut, using a residuum-infused astral diamond as a focus.

Effects

The caster chooses a point within 30 feet. A sphere of variable radius (no more than 1 mile across) centered on that point, becomes magically warded for the duration. Any creature or construct cannot enter the sphere unless they make a Charisma save against the spellcaster's spell save DC. Any fiend or undead attempting to enter the sphere has disadvantage on this check. Any magical effects, including those of an antimagic field or dispel magic, cannot penetrate or affect the sphere.

Spells function inside Lionni's divine shield as normal, but any creature attempting to target a creature outside the sphere has disadvantage on any attack rolls made against those creatures. The spell penetrates all barriers and extends into the Ethereal Plane.