The next New Heroes banner in Fire Emblem Heroes is “Special Summon: Ymir & More”, which runs from 19th July 2022 (UTC).
Note: You can check out the Japanese version of this trailer here.
In addition, Atlas: Forest Muscle can be summoned as a non-focus 3-star and 4-star Hero. Furthemore, the next Grand Hero Battle will feature Brigand Boss: Known Criminal.
Please continue for a breakdown of the Heroes from the trailer!