"Copy Knight" is a Trap Card that can be activated when you Summon a level 4 or lower Warrior-Type monster.

When activated, this Trap Card will be Special Summoned on the field, and will be treated as the same monster that you just Summoned.

If you activate this card when Summoning "The Six Samurai - Zanji," you'll have 2 "Six Samurai" monsters on the field, which will let you Special Summon "Great Shogun Shien."

Since "Copy Knight" has become a "Six Samurai" monster, you can also use it to protect "Great Shogun Shien."