Eureka is a girl born by the Scub Coral, a race of assimilating, intelligent, lifeforms that landed on Earth via falling satellite. She has pale skin, medium length aquamarine hair, and medium violet-red eyes. She wears a one piece dress that is blue and white. Also, she is the pilot of the Nirvash typeZERO Light Finding Operation. Eureka treats the typeZERO not like a machine, but as a companion or an intelligent being.
A bit of an enigma, Eureka is a lovely young girl who rarely shows emotion; she rarely smiles and never laughs. Eureka mostly speaks very calmly and directly never hesitating to speak her mind. She is often perplexed by other peoples emotions and behaviors. She understands machines better than humans, is more than an expert LFO pilot and used to be part of a Military Special Operations Force Unit untill she left with Holland. However, her physical and mental states undergo many changes after meeting Renton Thurston.
She is first appearance in Samuel's First Love. Samuel met Eureka for the first time along with Renten. In the episode, she was blushed at Samuel who save by Red Ranger and will be his wife. In the finale, he lost his husband from he melted until Samuel came back to life after John was resurrected into new Samuel.
She is now the main character almost Samuel until the second episode. However, after Renten is killed by Shadow the Hedgehog, she still love with him and see Renten spirit to good care of him.
Lightspeed Rescue and Time Force
She going to date with Samuel who defeating Mandy and Eustace. Acception with Samuel, she decide to marry Samuel who she saving her.
Wild Force, Ninja Storm and Dino Thunder
She changes her new outfits (cut by Super Sentai when she nudity in Gaoranger). However, since Samuel is badly injured, she anger at Mandy from revenge against her and goes into Hyper Saiyan. As she turned back, Eureka decides to calm easily. Unfortunately, Shadow is not dead yet and Samuel killed along with Lotherzord, but he survived and revealed Samuel seperating Storm Megazord's head to Hawkzord before it destroyed finally kills Shadow for good.
SPD, Mystic Force and Operation Overdrive
Samuel was alright about beening wounded by A-Squad Rangers.
Eureka's Original Form
This is Eureka's starting form. In this form Eureka looks just like a normal teenage girl with the exception of her hair, which is Aquamarine in color, and her eyes, which are Medium Violet-Red. However she is initially cold and distant as a result of her being unaware of much of what humans take for granted, like smiling, love, etc.
After being Attacked by Anemone and theEND
Eureka underwent a transformation after she and the Nirvash suffered damage from theEND. Mentally, she stopped trusting; and physically, her skin started being covered with slime and huge scabs that hindered her movement.
After Watching Renton Wounded
When Renton was badly wounded protecting Eureka from the new SOF Squad sent to gather Eureka's Bio Data and eliminate her, Eureka's love for Renton came back and she tore off the scabs holding her. The Result was that mentally, Eureka learned that love hurts but also can give joy; while physically, Eureka gained scars all over her body.
After being Absorbed by the Coral
After Renton saved Eureka from the Coral absorbing her, she is found to be covered in a cocoon like substance which is fused with her skin. Mischa was unable to remove the substance without harming Eureka so Holland decides to accept a mission to save a Vodarac High Priest. Once saved the High Priest performs a Guidance Ritual to release her. Free of the Cocoon, Eureka emerges scarred, with short light blue messy hair and lacking eyebrows. She bears this form untill meeting Sakuya.
After Meeting Sakuya
Before leaving Sakuya's Heart, Eureka is offered to have her scars fixed but she refuses saying that these scars are the outward proof of what she has been through. Sakuya responds by commending Eureka's strong will. Upon emerging Eureka is shown to have regained her former appearance. Her hair is now loose without the clips holding them back and her scars have become less prevalent.
After Reaching the Promised Land
Upon passing the Great Wall, via the Void, and reaching Earth, known as the Genuine Promised Land, Eureka undergoes her most intense transformation yet. First her left arm starts getting covered by green swellings. Afraid of what the others might think, she initially tries to hide them and then run away but the others soon find her and the secret is revealed. When Renton bashes his arm in an attempt to become like Eureka she understands that Renton would not turn away from her and reconnects with him. However Renton's injury gets infected and he develops a high fever as a result. While caring for a sick Renton, Eureka sheds a tear and her left arm completely morphs into corralian form, furthermore winglike appendages grow out of her back. Eureka is once more afraid of what Renton might think when he wakes up, but upon seeing her Renton is entranced and comments on how beautiful Eureka has become, much to her joy.
Eureka's Final Form
When Dewey dies, the collar on Eureka begins affecting Eureka's physiology and her skin morphs completely into Coralian green before she is enveloped in a sphere of black and red energy. When Renton and the Nirvash Spec3 force their way into the sphere, Renton encounters Eureka whose arm has turned back to normal but is still having her green wings. He ties her hair back with a hair clip revealing a small green gemlike spot in the middle of her forehead.
Renton Thurston, also known as the boy, is the so-called chosen one and the former soul mate of Eureka. He is also the protagonist in the story. Renton and Eureka's relationship is complex throughout the story. Started out as Renton having a big crush on a beautiful girl that crashed into his grandpa Axel Thurston's garage, Renton begins to understand how his role affects Eureka and that of the Nirvash TypeZERO. Because of this, Eureka begins to reciprocate Renton's feelings for her. It was because of Renton's love for Eureka and, later, Eureka's deep love for Renton that many of the impossibles happen like going to the promised land which is Earth, and saving the world from the Coralian exceeding the limit of life. Eureka never formally marries Renton, but the record book Axel Thurston wrote that Eureka was Renton's wife, and the kiss in Episode 50 with the lake scene allows viewers to presume Eureka and Renton are eventually formally married. However, in Power Rangers, Renten was killed by Shadow the Hedgehog. When Renten was killed, Eureka soon married Samuel Joo after she's feels happily.
Maurice, Mater, and Linck
Rescued children from a city named Ciudades del Cielo during the time when Eureka and Holland were still in the United Federation of Predgio Towers Special Forces which was renamed to as the Gekkostate when Holland decided to bail out of the military. Prior to Renton teaching Eureka how to discipline the children and being the male role model to the children, the kids were snotty and bratty. They tease and cause lots of trouble to the Gekkostate, especially Renton Thurston. Despite that, they love Eureka very much, even reffering to her as "Mama" and are very protective of her. Especially Maurice who was willing to kill Renton because he thought Renton was responsible for Eureka's transformation.
Eureka joined Holland Novak's special squad when she was found next to the Nirvash TypeZERO and seeing that she was the perfect pilot for the Nirvash. Holland always thought as being the partner of Eureka, but Norb states that Eureka will have a partner other than Holland and Dewey. It is the boy that makes her truly smile from the heart, that will become her partner. Still, Holland protects Eureka from harm and did not accept that Renton was her partner till the first half of Season 2.
Ever since Eureka was found, Axel Thurston was a part in building new technologies for the Nirvash TypeZERO. Adroc Thurston assists Eureka till his mysterious disappearance which was later found out that he was with the Scub Corals. There isn't much evidence whether or not Diane (Renton's sister) was seen with Eureka. It seems as though Eureka didn't know about Diane till Renton introduce Diane to Eureka.
Eureka has a special status in the Gekkostate, being one of the original members and how Holland Novak took care of her. She was also seen in the Gekkostate as being a mother to the adopted Maurice, Maeter, and Linck. After Renton's recruitment, she changed little by little. By Season 2, Eureka was seen with Renton more often than the first season.
Samuel Joo was the Red Ranger and the soul-mate Eureka after Renten was killed. Later, she finally married in Power Rangers: Super Samurai, but not before his parents shows up to "against" Samuel with their fully hatred and anger. However, Samuel saving her wife and taking his host body by Holland. After witness Samuel is heavily wounded, Admiral rescues both of them from killing by enraged people and anime people.
- Mostly like the Power Rangers, she was also same of Super Sentai.