The final confrontation with Colonel Sloan is a multi-phase boss battle. Sloan will likely be heavily armored, possibly augmented, and will utilize powerful weapons and abilities. Pay close attention to his attack patterns and look for environmental cues.
Phase 1: Sloan will typically engage you directly with a powerful weapon. Use cover to avoid his attacks and aim for headshots or exposed weak points. He might summon regular Omega Force soldiers to distract you. Clear them out quickly to focus on Sloan. Keep moving and use your syringes to heal when necessary.
Phase 2: Sloan might activate a shield or become temporarily invulnerable, requiring you to destroy environmental objects or specific generators to expose him. He might also unleash a Blood Dragon or other experimental creatures. Use cyber-hearts to turn the Blood Dragon against him if possible, or focus fire on the creatures to clear the arena.
Phase 3: In his final phase, Sloan will be at his most desperate and dangerous. He might charge you, use powerful area-of-effect attacks, or attempt to flee. Continue to exploit his weaknesses, use your most powerful weapons, and don't let up the pressure. Once his health bar is depleted, a final cinematic or quick-time event will trigger, concluding the battle and the main story.