Kyle teleports back after he is healed, and uses the red lantern to disrupt Piper's thought process and spell casting ability.
Kyle then attacks Piper with Fear, forcing her to see her worst fear, and as she has seen some grisly things as a witch, she breaks. Then, with Angel stuck in the crystal, Kyle changes to the Indigo Lantern and teleports Piper with him into space, where Kyle continues to blast her with fear, and Piper can't cast any spells, as she has been bound by lantern chain constructs since the start, with a blindfold and her mouth forced closed, she is helplessly suffocating and being blasted with fear, to the point that she couldn't use magic even if she wasn't bound and was on earth. Piper dies quickly, and leaves behinds pieces of her corpse. Kyle gathers those pieces up with his ring, and catapults them into the sun, making it next to impossible to revive her.