Interestingly, its clapper glows while being wielded in battle.
The Awakening Bell + is Marin's Level 4 Bell in Hyrule Warriors Legends. It is basically a stronger plus version of Marin's Level 3 weapon. Like all Level 4 weapons, it has the same design as the Level 3 weapon it is based on.
Marin wielding the Awakening Bell in her victory cutscene from Hyrule Warriors