First Seen: Sonic the Hedgehog (2006)
When she was seven years old, she was with her father, the Duke of Soleanna, when he tried to extract energy from the sun god of Soleanna, Solaris. The experiment accidentally splits the deity in two entities, but the Duke manages to transfer one half, Iblis, into Elise. He then tells her that she must never cry, as that would release the destructive Iblis, also known as the "Flames of Disaster."
In the present time of the game, Elise celebrates the Festival of the Sun in Soleanna. Doctor Eggman then attacks the city and kidnaps Elise, out to get her Chaos Emerald and the power of the Flames of Disaster locked inside her. Sonic the Hedgehog quickly chases after them. Elise is later killed when the Egg Carrier explodes, but Sonic and Silver use Chaos Control to go back in time and save her.
In the "Last Story", Sonic is killed by Mephiles, the other half of Solaris. Elise breaks down and cries, releasing Iblis, who fuses into Solaris with Mephiles. After Sonic's friends find the seven Chaos Emeralds, Elise uses their powers to heal Sonic, and with the help of a kiss from Elise, Sonic became healed as Super Sonic (Elise heals him with the seven Chaos Emeralds), and then Super Sonic gives some of his power to Shadow and Silver, transforming them into Super Shadow, and Super Silver. After Solaris is destroyed by Super Sonic, Super Shadow, and Super Silver, Sonic and Elise go back in time to when Solaris was just a flame. Elise takes the flame and tells Sonic that if it blows out, the flame that will become Solaris in the future, it will result in her and Sonic never meeting. Though she doesn't want their friendship to end, Sonic convinces her to abandon their meeting. With tears in her eyes, Elise gently blows out the flame, which removes Solaris from existence, thus erasing the whole game's events and happenings. Afterwards, the timeline changes so she is never kidnapped, and never meets Sonic. All the events of the game never happened.
Princess Elise makes a small cameo in Sonic Rivals 2 as a collectible card.
In SEGA's Sonic '06 game script spreadsheet file, there are character profiles written in corresponding English and Japanese that talk of their personalities and some of their origins. In the end of Elise's English profile, emphasizing her role in the story, it says, "On one side, she is a prim and proper princess, but on the other, she is a typical confused and anxious 17-year-old girl. [sic] She tries to make light of her fate, but her encounter with Sonic is what shall truly set her soul free."