Concise: (20 seconds.) Target ally has +10...34armor against slashing damage. Renewal: Whenever a chant or shout ends on that ally. Cannot target spirits.
Slashing damage is the most abundant damage type from melee weapons. All scythes, all swords except the Jitte, almost all axes, and half of all daggers not upgraded to do otherwise inflict Slashing damage. As such, it is highly advantageous to keep this refrain active.
It is recommended that you switch to an elemental weapon, such as Ebon, when facing enemies using this skill, as this will bypass the armor boost it grants.