Seol Hee is a superhero appearing in American comic books published by Marvel Comics. Created by writer Greg Pak and artist Gang Hyuk Lim, the character first appeared in War of the Realms: New Agents of Atlas #1 (May 2019). Seol Hee is a superhero of South Korean origin. She is a K-Pop idol who possesses ice-based superpowers. She is known under the stage name Luna and the codename Luna Snow.
 The name of Seol Hee translates to "snow" and "hope" in Korean. She first appeared as an original character in the video game Marvel Future Fight in 2018. The South Korean mobile game developer Netmarble requested an "ice magician who could both heal and deal damage" for the game. She was also created in response to comic book readers asking for more characters that are more culturally diverse. Marvel Games Executive Creative Director Bill Rosemann commented on her debut, "Marvel has the greatest fans around the world, and they deserve heroes that they can not only cheer on as they fight evil, but also connect with on a personal level." Marvel Entertainment subsequently released several promotional singles for Luna Snow. Seol Hee was later introduced in the Marvel Universe in 2019.
 Seol Hee debuted in War of the Realms: New Agents of Atlas #1 (May 2019), created by Greg Pak and Gang Hyuk Lim. She later appeared in the 2019 Agents of Atlas series. She appeared in the 2019 Future Fight Firsts: Luna Snow one-shot, her first solo comic book. According to Diamond Comic Distributors, it was the 140th best selling comic book in October 2019. 
 Seol Hee appeared in the 2020 Atlantis Attacks series. She later appeared in the 2022 Silk series. She appeared in the 2022 Marvel's Voices: Identity anthology series. She appeared in the 2022 Tiger Division series.
 Seol Hee was raised by her grandmother after the deaths of her parents. She was an aspiring singer who wanted to support her family financially. She later became an idol under the stage name Luna.  
 During a live performance at Stark Arena, Seol Hee became the hostage of the supervillain organization Advanced Idea Mechanics (A.I.M.), after she attempted to defend the attendees from the event. She was trapped inside a malfunctioning cold fusion reactor. Hee gained ice-based superpowers while trying to escape. She later defeated the A.I.M. forces and became known as Luna Snow.
 Seol Hee fought with Crescent and White Fox against demons coming from Muspelheim. She was initially captured by Sindr before Amadeus Cho rescued her. She used her superpowers to prevent the North Pole's polar ice from melting with the help of Aero and Wave. Seol Hee and the other Agent of Atlas later defeated Sindr.
 While she was in Tokyo, Luna Snow battled a group of wyverns after Mike Nguyen started merging various Asians cities within the city of Pan.
 Seol Hee possesses ice-based superpowers. She has the ability to generate dark ice with destructive effects and light ice with healing properties. Additionally, she is an accomplished singer and dancer.
 Tim Webber of Comic Book Resources named Seol Hee one of "Marvel's most prominent South Korean characters," while Noah Dominguez called her a "fan-favorite" character. Madeline Ricchiuto of Bleeding Cool stated that Seol Hee received "positive fan reception." Previews World called Seol Hee a "fan-favorite character." Angela Davis of Screen Rant described Seol Hee as a "fan favorite hero."  
 Jon Arvedon of Comic Book Resources called Luna Snow a "fan-favorite South Korean K-pop sensation." In January 2023, her singles "Tonight" and "Flow feat. Luna Snow (Space Remix)" reached respectively more than 86 000 and 41 000 views on YouTube.
 In June 2023, it was rumored that South Korean singer Jennie would portray Seol Hee / Luna Snow in the Marvel Cinematic Universe (MCU). YG Entertainment officially denied the rumor a few days later by stating that Marvel never made such an offer. However, several media outlets later reported that the agency has been in talk with Marvel since 2021 but refused to let Jennie work with the studio due to her schedule.