Amunet the Dungeon Master

When you cast an instant or sorcery spell that
targets a permanent, venture into the dungeon.
As long as you've completed a dungeon, instant
and sorceries you control cannot be countered
and their damage cannot be prevented.
Even the kindest heart rages. Even the most giving
soul has limits. Woe to whomever awakens hers.
They will wither within a dungeon without escape.