Lost Lore

"Send Heroes to scout out other worlds and recover their lore!" Lost Lore is a passive game mode introduced in Version 3.8.0. It was first presented in Feh Channel (Aug. 1, 2019).

In this mode, heroes can be sent on timed scout missions to certain Fire Emblem worlds to gather story information from those worlds' related games. These missions occur passively and without additional player input once they are started.

Scouts
Send Heroes on other worlds to find lines. Up to three teams can scout at the same time at different locations. Each team can contain one or two heroes, but the same hero can't be on two different teams. If two heroes on the same team have a Ally Support, their bond will increase each four hours. That means two heroes with a new bond will see their ally support rank passed from C to B after 24 hours. Scouting teams will recover lines proportionally to the time of the scout, no matter the number of heroes and their stats. Even when the application is closed, teams continued their scouts:
 * A 12 hours scout yields 12 lines.
 * A 20 hours scout stopped after 15 hours yields 15 lines.
 * A 2.5 hours scout yields 2.5 lines (only rounded numbers are displayed, but decimals are saved).

Moreover, if at least one hero of the team is from the world of the scout, lines earned are increased by 20%. By example, if is doing a 12 hour scout on the World of Mystery, he will bring back 14,4 lines.

Strikes
Strikes are passive turn-based battles that appear as a world's final act. These battles adjust characters' stats to specific parameters, disregarding their level or rarity. These stats are likely based off of their neutral stats at level 40. This also means that passives are irrelevent to calculations during battle, though the weapon triangle and effectiveness will still effect damage. Critical hits and dodges will also sometimes trigger during battle. Sending heroes from the corresponding world and Ally Support partners into battle will increase their stats during strike missions.

Scouting / Striking
After a scout/strike is completed, players are rewards with various items. The number of items earn depends of the time spent, and are randomly chosen between these:

Scouts
After a scout, one of these lines is displayed randomly:

This time, they: If only one hero was sent, it is noted:
 * collected stories about respected individuals.
 * took note of the details of the surroundings.
 * encountered and studied an unusual creature.
 * got lost—but were rescued by someone kind.
 * passed spare time doing intense training.
 * shared tales from home in the evenings.
 * spotted an abandoned weapon. Whose was it?
 * stumbled upon a beautiful stone along the way.
 * uncovered traces of a desperate struggle.
 * overheard information about the local celebrity.
 * gained experience that will be useful later on.
 * wished upon a star for success in the future.
 * got tied up in their excitement to investigate.
 * grew tense from being in an unfamiliar world.
 * marveled at the fresh sights of the other world.
 * argued fiercely over how to best investigate.
 * devised an ingenious strategy for investigating.
 * gained a deeper understanding than expected.
 * enjoyed a veritable feast together.
 * spoke about the future in the evenings.
 * came to understand each other a bit better.
 * returned ready and raring for the next time.
 * Try sending out two Heroes next time!

Strikes
After a strike, one of the following lines is display, depending on the number of foes alive:
 * 4 foes alive: The foes are still going strong! Just keep at it!
 * 2 or 3 foes alive: The foes are weakening! Don't let up!
 * 1 foe alive: Only one foe remains! This is it!
 * 0 foes alive: All foes defeated! Strike complete!

Trivia

 * Although 's in-game Origin value corresponds with, there is a file in  that allow her to be counted among the bonus title Heroes for the World of Mystery to match her list of appearances in her description.