Without having a second set of weapon, a nice way to have a third no-swap class would be to have every weapon with 2 different set of skills, similar to elementalist attunement.
Each Revenant weapon could have 2 (or more) set of skills. Skill sets can change according to the current legend.
Defensive legend -> weapon skill set 1
Offensive legend -> weapon skill set 2
Example:
Hammer Revenant could have a melee action set for shiro and demon, while having a ranged skill set (like the current one) for ventari and dwarf.