Decided I'd put my idea on what the "Heroic Legacy" may look like. I decided to base the route on iconic moments from previous Fire Emblem games:
Battle 1: vs.
![Marth :ultmarth: :ultmarth:](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
on Tortimer Island (omega) with Lords-A Chance Encounter playing (based on Marth Embarks, the first Fire Emblem chapter ever)
Battle 2: vs.
![Roy :ultroy: :ultroy:](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
on Castle Siege (Lava portion) with Beyond Distance Skies playing (based on Chapter 8x of the Binding Blade, where Roy gets Durandal)
Battle 3: vs. a giant
![Ike :ultike: :ultike:](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
with his 8th palette, with
![Ike :ultike: :ultike:](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
(default) and
![Villager (Female) :ultvillagerf: :ultvillagerf:](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
as allies, on the indoor portion of Castle Siege with Against the Dark Knight playing (based on the battle with the Black Knight in Path of Radiance)
Battle 4: free for all with
![Chrom :ultchrom: :ultchrom:](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
,
![Robin :ultrobin: :ultrobin:](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
, and
![Lucina :ultlucina: :ultlucina:](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
on Arena Ferox with Id Purpose playing (not based on anything in particular, just thought it worked well for the Awakening battle)
Battle 5: vs. red
![Chrom :ultchrom: :ultchrom:](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
and gold
![Simon Belmont :ultsimon: :ultsimon:](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
, with
![Corrin :ultcorrin: :ultcorrin:](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
as an ally, on Coliseum with Lost in Thoughts All Alone playing (loosely based on the first battle of Fire Emblem Fates: Revelation, where Corrin has to stop Xander and Ryoma from fighting)
Battle 6: free for all with 3 Byleth using the Edelgard, Dimitri, and Claude palette on Garreg Mach Monastery with Edge of Dawn playing (no need to explain what this is based on!)
Boss: Rathalos, to represent how dragons are the final boss in many Fire Emblem games.