Can we embed VBCS custom page in the Login Page of SaaS Fusion Instance?

Summary:

We have a requirement to capture the login details (login name, time of login), along with purpose of login (additional custom fields, for which issue, details if any of any action to be done) into an Oracle Fusion Instance into a table. So we need to add two or more fields and make them mandatory based on the login user name provided in the user name field / upon clicking login, show a dialog window with two mandatory fields to be provided based on the logged in user. The information entered by the users in these two new fields,