How can I create passwordless users and restrict them from login using "su"?

Issue

• How to create a user ID with no (NP) password?

• There is a option like passwd -d (user ID) or passwd -u -f (user ID), to set no password. But in this option any user can able to do su with any other available ID's. Is there any other way to restrict local users to do an su to other passwordless local users.