In the Name of the Hero-King
From SmashWiki, the Super Smash Bros. wiki
In the Name of the Hero-King (known as In the Name of Marth! in PAL versions of the game) is a single-player event match in Super Smash Bros. for Wii U. In it, the player controls Marth, and must defeat Lucina in a 200 HP battle.
The description and concept of the event references how Lucina disguised herself as Marth when she initially appeared in Fire Emblem Awakening.
Completing the event on hard difficulty awards a Safe Respawner Cape equipment.