[TIP] "COMMAND KNIGHT" "Command Knight" has an effect that increases the ATK of all your Warrior-Type monsters by 400 points, including herself! Such a good effect will make this card the first monster your opponent will want to attack.
But "Command Knight" has a second effect, that says she cannot be attacked if you control another monster. This means that if you have two "Command Knight"s on the field, neither can be attacked by your opponent! Look for ways to Summon 2 "Command Knight"s using cards like "Reinforcement of the Army".