This foundation is then elevated to an art form by the **Nightmare Dungeon** system. By using consumable **Nightmare Sigils**, players can empower any normal dungeon, adding multiple challenging affixes and scaling its difficulty and rewards dramatically. These affixes are the true test of a build's versatility. One sigil might make monsters explode on death while another causes walls to periodically imprison players. This demands constant adaptation; a build that excels in one **Nightmare Dungeon** might struggle terribly in another, pushing players to consider defensive layers and mobility as carefully as raw damage output. The primary reward for conquering these gauntlets is experience for **Paragon Glyphs**, the powerful, level-upable jewels that slot into the Paragon Board, directly tying dungeon success to permanent character power.