Seven Knights

Seven Knights (, ) is an online free-to-play role-playing game created by Netmarble. It was released for Android and iOS devices in March 2014 in South Korea and in February 2016 in Japan. An anime television series adaptation by Liden Films and DOMERICA titled "Seven Knights Revolution: Hero Successor" premiered on April 5, 2021.
Premise.
Long ago, the evil goddess Nestra and his cult, Physis, attempted to destroy the world until they were stopped by the Seven Knights, warriors chosen by the goddess Serrass. Generations later, the Seven Knights are worshipped as heroes by Granseed Academy, an institution that trains the next generation of warriors. Granseed's student council is the next generation of Seven Knights, and they channel the power of the original heroes through the process of Succession, which bonds the soul of the current hero with the soul of the original hero with a special card. This new generation of Seven Knights enters into conflict with Physis, which is spreading its influence throughout the world yet again.
Anime adaptation.
On February 4, 2021, Netmarble announced that an anime television series adaptation titled and produced by Liden Films and DOMERICA was announced. The series is directed by Kazuya Ichikawa, with scripts overseen by Ukyo Kodachi, character designs handled by Arisa Matsuura, and music composed by Yoshiaki Fujisawa. It premiered on April 5, 2021 on Tokyo MX and other channels. Flumpool performed the series' opening theme song "Freeze", while Daiki Yamashita performed the series' ending theme song "Tail". Muse Communication has licensed the series in South East Asia and the anime is scheduled to be streamed on their YouTube channel. Crunchyroll licensed the series outside Asia.