Fire Emblem Heroes will start a summoning event on July 18 at 16:00, including the Leaf of the Hibiki Hero and the Mature of the Demon Hero.

Fire Emblem Heroes will start a summoning event on July 18 at 16:00, including the Leaf of the Hibiki Hero and the Mature of the Demon Hero.
 Nintendo announced today (July 17, 2025) that it will be holding a new hero summoning event "Hibiki Hero & Demon Hero & Melière" on the smartphone app "Fire Emblem Heroes" from 16:00 on July 18th to 15:59 on August 7th. This time, Leaf, a Echo Hero, Mature, Rinoan, a Demon Hero, and Meliae from FE Heroes will participate in the battle....

The linked article is in Japanese.