Another day, another conquest it seems for Fire Emblem Heroes as a new trial is set to come on June 8th. This will be slightly different to all of the others that have come before as this time, if your allies fall in battle, you will not be able to revive them to use again as you progress through each of the maps in the trial. The full details about the Tempest Trials can be read below which we extracted from the In-Game Notification tray.
Source: Fire Emblem Heroes In-Game Notification