Blue Steel Blade is built for aggressors facing enemies who hide behind Eight Trigrams, since your Attacks punch straight through the armor and only a real Defense can stop them. Its range 2 also lets you reach a target one seat farther out. A Rebel hunting a Lord who leans on Eight Trigrams wants it most, as does any Lord or Traitor who needs to crack an armored defender.
Pair it with relentless attackers like Zhang Fei or Guan Yu so every swing tears through Eight Trigrams. Lu Bu fits even better — his Attacks already force two Defenses, and with the armor dodge gone the target has almost no way out. Add Red Hare to stretch range 2 onto a far-seated target.
Against this blade, stop leaning on Eight Trigrams and keep real Defense cards in hand, since armor no longer saves you. Slip outside its range 2 by equipping Shadow Runner, or strip the weapon first with Dismantle or Steal before it ever swings.