Spell Details
Effect
You inscribe a visible sigil that excommunicates magic within its reach. The area becomes a zone of true antimagic:
Spell Suppression: Spells can't be cast inside. Ongoing spell effects that enter are suppressed while inside; spells or effects originating outside that target creatures or objects inside are suppressed at the boundary and fail to take effect; teleportation, portals, scrying, and planar travel into/out/through fail. Focus note: Suppressed effects don't end globally; if the caster and effect leave the zone and duration remains, they resume.
Magic Items: All magic item properties are suppressed while inside (no bonuses, properties, or charges). They resume when removed from the area.
Conjured/Extraplanar: Such creatures cannot enter. If present when the seal is created, they are placed at the nearest safe unoccupied space just outside the boundary.
Impartial: The seal suppresses everyone's magic, including the caster's.
Backlash:
If a creature attempts to cast a spell or activate a magic item inside the area (or project a spell into it), it triggers backlash (Mind TN 15): on fail, take 3d6 radiant or necrotic (your choice on casting) and gain Weary (-2 to all rolls); on success, take half damage and no Weary. The attempt fails either way. Max one backlash per creature per round.
Counterplay:
Break the Seal: The inscribed sigil is fixed to a surface and has AC 10, 30 HP. It can only be harmed by nonmagical sources (mundane weapons, tools, siege engines, fire, falling stone) -- magical damage has no effect while the seal is active. If the surface moves, the sphere moves with it. Destroying the sigil ends the spell immediately.
Desecrate the Mark: Spilling defiled oil or ash on the sigil and succeeding on a Body or Mind test (TN 15) suppresses the seal for 1 minute; it then resumes unless destroyed.
The seal cannot be dispelled - it is the area itself, not a spell effect within the area.
Special Notes
You can cast this spell once per week and maintain only one active seal at a time. You cannot create a new seal within 1 mile of any existing Seal of Unmaking, or within 1 day of ending another seal in the same mile. Forbiddance effects, dimensional locks, antimagic anchoring, or rival divine sanctums of equal or greater standing can block or suppress the seal at the DN's discretion. The seal is obvious within 300 feet - the sigil hums, the air runs cold, flames gutter. Overlapping seals don't stack; the strongest applies.