As the fight progressed, it became worse and worse to look at. No matter what the boss did, be it the party wipe skill or something else, Shiro had a counter for it. If it tried to use earthquake, her hidden contraptions would stun him, causing his skill to fail.
With Shiro taking care of all the minions and targets, both Yin and Lisandra just needed to fire their skills at will.
Yin's Dark Star Element and Shadow Element weakened the boss's defences immensely due to their corrosion effects. As for Lisandra, her support skills and sword buffs allowed her to cause the boss massive amounts of damage.
With both of them working together, the armour was nothing but decoration.