Actually, both the Revolutionary Firebrand and Secular Missionary have Persuasive boosts of 9 when you upgrade them at the Feast of the Exceptional Rose. That’s the highest boost any Persuasive companion bestows, with all the rest being tied to Professions.
I forget if you need to speak to both the Missionary and the Firebrand for the storylet to trigger, but there’s not Intimate requirement on the option that gives you the Secular Missionary companion so there’s no harm in doing so. I would still recommend sending an email to support@failbettergames.com just to be sure.
edited by Sara Hysaro on 3/9/2015