The Zweihander is found on page 100 of the Eisen source book, and has the following rules text:
However, after every attack made with a zweihander, the Hero must either spend one Action to reset it before it can be used to attack or parry with again, or else drop the zweihander and switch to another weapon.
[the example character uses his zweihander to attack]. Now he can neither attack with the zweihander nor use his Parry (Heavy Weapon) Knack until he spends one Action to reset the zweihander.
What forms of passive defense, if any, can a character with a zweihander waiting to be reset perform? Can they still use their Parry (Heavy Weapon) passive defense? Can they use Footwork (passive or active)? Or are they a sitting duck until the zweihander resets?