Fire Emblem Heroes has received a content update for March 24th, 2022. You can see full details on this update below.
[Summoning] A new Summoning Focus is now live: Heroes with Null Follow-Up. It features the following Heroes: Nyx (Rulebreaker Mage), Corrin (Bloodbound Beast), and Dieck (Wounded Tiger) (available until April 2nd)
[Story Maps] The latest Tactics Drills map is now available: Hero-King Killers (Grandmaster) (no end date)