Complex sentence: After obtaining the Varia Suit in the ruins, Samus finds her way to the Magmoor Caverns, a series of magma-filled underground tunnels, which are used by the Space Pirates as a source of geothermal power and connect the game's areas together.
Split into simpler sentences: After obtaining the Varia Suit in the ruins, Samus finds her way to the Magmoor Caverns, a series of magma-filled underground tunnels. The Caverns are used by the Space Pirates as a source of geothermal power, and connect all of the game's other areas together.