When Skipper came to Kauai, he explained his and Jumba's past to Lilo and Stitch, including the creation of Experiment 628. Cobra later arrived to inform them that Hamsterviel was indeed on Kauai somewhere, and Lilo, Stitch and Skipper left on a manhunt for Hamsterviel's hideout. When Lilo and Skipper were alone, Skipper questioned Lilo about her feelings for Stitch, and admitted that he himself liked Angel.
The manhunt ended in disaster when, while Stitch had left to visit Angel, Lilo and Skipper were attacked by 628, infected, and rendered unconscious. When Stitch and Angel found what had happened, they took Lilo and Skipper back to the ship until they woke up.
After Lilo recovered and awoke from the attack, a reluctant Nani (apparently) explained to Lilo over dinner what Jumba had found out about 628; due to the attack on Lilo and Skipper, they would both inevitably transform into experiments the following night.Lilo and Skipper spent the five hours they had left as humans surfing with David, before returning home for their transformation. Jumba used Drowsy to put Lilo and Skipper to sleep (so they would not be conscious to feel the pain of their transformation), then set up a system to wake the two up the next morning. Minutes later, Lilo and Skipper excruciatingly transformed into genetic experiments in their sleep, and after taking DNA samples from them, Jumba left them to sleep.
Lilo and Skipper awoke the next morning, and, after seeing the full extent of their transformation in a mirror, went downstairs to greet the others. Lilo and Skipper had breakfast, during which Lilo tested her new experiment abilities by eating a plate. Once they were finished, Jumba took them to his ship to test any new powers they had.
After they finished, Stitch and Angel decided to go for a walk, to Lilo's anger. Lilo and Skipper then began arguing about how they felt for Stitch and Angel, and made a deal: when one of them told their love interest how they felt, the other would have to do the same.
That night, Skipper awoke Lilo, Stitch and Angel to reveal that he had discovered Hamsterviel's hideout. The four spent the rest of the night and most of the morning planning an attack on the hideout, until Gantu and Reuben arrived.
They explained what had happened to Lilo and Skipper, before launching their attack on Hamsterviel's bunker that night. They split into two teams, with Lilo's team going in the front door, and distracting Hamsterviel's forces before meeting up with the other team in the control room.
However, once they reached there, they were confronted by Hamsterviel and his new experiment, Smasher, who easily shrugged off the experiments' attacks. Eventually, as the experiments began to tire and their attacks became weaker, Smasher attempted to kill Stitch by impaling him with a projectile bone.
As Lilo rushed to a dying Stitch's aid, she telekinetically stopped the bleeding, then, enraged, turned her attention to Smasher. Lilo's rage and hatred allowed Athena (a mental manifestation of Lilo's dark side, created by her transformation into an experiment) to temporarily take control.
After telekinetically crushing Smasher into oblivion, Lilo/Athena attempted to telekinetically choke Angel, causing Skipper's dark side (Apollo) to take control in his fit of rage and attack Lilo/Athena. The two experiment hybrids fought, with Lilo/Athena telekinetically blocking Skipper/Apollo's attacks.
Eventually, Angel sung her song backwards, causing Lilo and Athena to fight for control inside Lilo/Athena's head until Lilo retook control. However, Skipper/Apollo, in his rage, continued attacking Lilo until Angel calmed him down.
However, just then, Hamsterviel fled the bunker and revealed a bomb that would destroy the bunker and kill everyone in it if they didn't stop it. Skipper subsequently sacrificed himself to stop the bomb, leaving Lilo and Angel in tears before they were comforted by Stitch and returned home.
The next morning, Lilo and Angel were both still upset over the previous night, especially once they discovered from Jumba and Stitch that Hamsterviel had captured Reuben. To lighten the mood, Lilo, Stitch and Angel spent the day swimming at the beach, and Lilo used her telekinetic abilities to help a reluctant Stitch swim.
Lilo is described as an Angel look-alike with darker fur, a retractable second pair of arms, slightly shorter antennae, dark back markings, and front markings a slightly lighter pink than the rest of her body.
Lilo has primarily mental and telekinetic powers, as well as Angel's song and increased intelligence and mental capacity. She can also scale walls, and has night and heat vision.
- When Athena temporarily took over, Lilo showed the ability to telekinetically choke people. This may be based off Darth Vader's Force Choke from the Star Wars franchise.