That’s all Falcom confirmed, but we have a rough idea of how many characters are in Ys vs. Sora no Kiseki. The character page on the official site shows eight boxes for Ys characters and eight for Sora no Kiseki’s heroes. So, 16? That means Falcom has 10 more to announce. Two other characters were accidentally revealed in this screenshot.
Ys vs. Sora no Kiseki: Alternative Saga is due in Japan on July 22.