Create a massive floating arcane fortress core — a jagged, blackened stone monolith with colossal golden mechanical rings orbiting it, engraved with glowing runes in shifting languages. Between the rings, rivers of molten crystal flow upward against gravity, breaking into shards that hover mid-air. The core’s center is a swirling galaxy-like vortex of blue, purple, and green energy, with occasional lightning arcs. Fractured platforms of obsidian and ancient marble orbit the structure, chained together by ethereal, ghostly links that fade in and out of sight.