The final confrontation with GLaDOS is a multi-stage puzzle battle. Your objective is to destroy her core components, which are represented by glowing spheres that detach from her body. There are four cores in total. Each core needs to be picked up and thrown into the Incinerator. The challenge comes from GLaDOS's defenses and environmental hazards.
Phase 1: Morality Core
GLaDOS will drop the Morality Core. It will bounce around the room. You need to use portals to redirect Energy Pellets from the dispenser into the core. Once hit, the core will detach. Quickly grab the detached Morality Core (press 'E') and throw it into the Incinerator, which is usually located on a lower level or behind a portal-accessible wall. GLaDOS will react with anger and activate new defenses.
Phase 2: Curiosity Core
GLaDOS will activate turrets and try to crush you with moving panels. The Curiosity Core will detach. Use portals to avoid the turrets and the crushing panels. The core will often be in a hard-to-reach spot. You might need to use momentum flings to reach it or to get a clear shot with a portal. Once you grab the Curiosity Core, throw it into the Incinerator. GLaDOS will become more aggressive.
Phase 3: Logic Core
This phase often involves rocket turrets. GLaDOS will fire rockets at you. You need to use portals to redirect these rockets back at GLaDOS herself. Place a portal on a wall where a rocket is about to hit, and another portal on a wall facing GLaDOS. The rocket will travel through and hit her, causing the Logic Core to detach. Be quick, as rockets are fast. Once the Logic Core is detached, grab it and throw it into the Incinerator.
Phase 4: Anger Core
The final core, the Anger Core, will detach. GLaDOS will be in a frantic state, throwing various objects and trying to crush you. This phase is often a chaotic combination of previous mechanics. You might need to redirect rockets again, avoid falling debris, or use precise portal flings to reach the core. Once you grab the Anger Core, make your final throw into the Incinerator. This will trigger the final sequence and lead to GLaDOS's defeat. Stay agile and keep your portals active!