I am here to discuss that Karen and Tokio from Time Bokan will appear as supporting heroes to help Lady Yuinshiel Asteria, Marika Kato, Wataru Kurenai, and many heroes to find and notify the truth about the Zoalords' and MetsubouJinrai.NET's newest weaknesses.
Yes. The heroes will have a final card game battle against Sima Yi from Legend Heroes. The epic crossover event can be based on Yu-Gi-Oh! Event, The Duel with Dartz Event from the Orichalchos Arc. I hope Ruko Kominato and Yuasaku Fujiki/Playmaker can duel after the souls of the Symphogear Heroines', the innocent Duelists' and many antiheroes'/villains' soul were taken by the Seal. So that, Playmaker will be defeated by Sima Yi before letting his soul be taken away by the Seal of Orichalchos. Ruko Kominato can activate the Legend of Heart to Special Summon the Legendary Knights of Atlantis to win the Duel against Sima. Timaeus, Critias, and Hermos will appear as allies to Sento Kiryu, Milinda Brantini, and many heroes.
In my crossover LOTM tales, Sima Yi will be destined to kill the Zoalords and other villains by betraying them, including Lu-Sho. So that, he will assist the Signer Dragon Duelists and the remaining Zoalords in a war against Yuinshiel Asteria and her followers.
I think the Deathly Events of the Seal of Orichalchos Incident will happen to the DigiDestined and many heroes, including Mai Natsume and Cajun Faycott. So that, the cursed incident will be caused by Sima Yi.