This is Missable, as when you get to Satans for the first time and need an extra invite, you have two choices:-
Help Fela the Demon OR
Help Lynda the Human.
Choose to help Lynda and go through her story. Its easy enough from that point.
Go to 58:00 (On Part 1) to see the start of Lyndas quest if you get confused.
Another playthrough is required then to help FELA the Demon and that achievement.