Phase 1: Tail Attacks
Corpius is your first major boss. Its primary attacks involve sweeping its venomous tail across the arena. Dodge these by jumping or sliding. It will also occasionally slam its tail down, creating a shockwave. Jump over this. Focus your fire on its head. After taking enough damage, Corpius will expose a glowing core on its tail. Hit this with missiles for significant damage. Be ready for a melee counter opportunity when it lunges.
Phase 2: Stealth & Venom
Corpius will turn invisible and try to ambush you. Use your Pulse Radar (if acquired) or listen for its movements. It will also spit venom pools that damage you. Continue to target its head and exposed tail core. The arena will shrink as venom covers the floor. Stay on the platforms and use wall jumps to avoid damage. Keep up the pressure and utilize any melee counter opportunities to deal massive damage.