...we don't need more three-stage modules.
The idea behind this module is that you're doing 3 stages of a password-like module, except some positions are covered up, and unlocked in later stages.
For example, if the passwords were COLOR, BOOLEAN, and DISREGARD, the stages would look somewhat like this:
CO=L==OR=
BOOL=EAN=
DISREGARD
Positions will open up, but never close.
The submitted letters from the previous password do not change when advancing a stage, but the unsubmitted letters do.