How to Beat Dyseosus, Champion of Cunning

Test Chamber 13: Place portals as shown to redirect a laser into a time portal. Travel through the time portal to the future. Rearrange portals in the future to direct the laser into the target, then exit through the door.

Test Chamber 14: Travel to the present via a time portal. Summon a reflector cube and position it to redirect a laser through the first node. Travel to the future. Use portals to bring a laser into the present through the time portal, ensuring it passes through the node. Retrieve the reflector cube from the future and bring it to the present via a time portal. Position the present reflector cube to hit all three nodes. Travel back to the future to retrieve the future reflector cube. Return to the present and place the future reflector cube to reflect the laser into the receiver, completing the chamber.

Test Chamber 15: Pass through the particle field to the left. Place a portal where the laser hits the wall and a time portal on the opposite wall. Travel through the time portal to the future to bypass the particle field. Move to the other side of the room and use another time portal to return to the present, now on the other side of the particle field. Place a portal to direct the laser to the first receiver. Travel to the future and place a portal in the laser room to shoot the receiver. Return to the present. An elevating platform will activate; stand on it and place a time portal behind the node to raise the platform further, allowing you to summon a reflector cube. Place this cube on the lip above the second receiver. Travel to the future. Retrieve the future reflector cube and bring it back to the present using a time portal in the laser room, positioning it to direct the laser to the second receiver through the node. Return to the present on the other side of the particle field. Climb the stairs and place a portal on the upper wall to hit the third receiver. Move the reflector cube onto the switch to complete the chamber.