Note: This is a backdated article.
The next New Heroes summoning event features additional characters from The Sacred Stones.
(Japanese trailer available here.)
The New Heroes include: Gilliam, Syrene, Vanessa and Rearmed Tana.
Additionally, Vigarde can be obtained from the upcoming Grand Hero Battle.
Update: Until 22nd April 2023 (may be earlier depending on your timezone), you can claim a free copy of Fomortiis, winner of the “A Hero Rises 2023” Voting Gauntlet, from the in-game Present List.