A guide to L!Marth's abyssal diffuculty map. Note that AI may change depending on your stats, dancer, IV, etc. Merges on B!Lyn and Rein are not needed, and can be subbed via alternate way.
Heroes
Ike (5 star) Neutral IV
Ragnell
Reposition
Radiant Aether
Warding Breath
Seal Att/Def 3
Def. Tactic 3
QR3 (Needed)
P!Azura (5 star) [Can probably be switched for Olivia] +Attack. -Defence
Urør
Dance
Blazing Flame
TA 3
WOM 3 (Needed)
Drive Sp. 3 (Needed)
Drive Def. 3
Reinhardt (5 star +1) +Attack. -Resistance
Dire Thunder
Draw Back
Blazing Thunder
Death Blow 3
Lance Breaker 3
Goad Cavalry
+3 attack (Can be switched to make Lyn live)
B!Lyn (5 star +2) Neutral IV
Brave Bow+ (Not sure if normal BB works)
Reposition (Needed)
Luna (Needed)
Swift Sparrow
Desparation (Needed in conjunction with BA)
Hone Calvalry (Needed)
Brash Assault 1
*Needed = Needed Uninherited Skills Or SS