I'm a P and I'm an 8.
I'm waiting for Babylon Candles to prove to me that my "MBTI + enneagram" constitutes a paradox.
ive had lengthy debates with you (ENFP), an INFJ and one other person on this board about this before...
IMO, being an 8 basically IS having inferior Fi. Others simply don't agree with my assumption, so its hard to really convince them besides laying out the theory of enneagrams being inferior functions.
for 8's: they are very "all or nothing", too much, too loud, too late (staying up), too intense. This isnt the kind of too much of an ENFP or ENTP, its too much as in 8's just have no ability to gradient inferior Fi. This is where ENTJs can be complete assholes about something normal, but then get really stirred up by some 'underdog story'. 8's also have issues with being controlled. they are known having that 'incredible hulk' moment, where they just AAAHHHH!!!!! and break free of a percieved something that is going to control them.
thats all pretty much the most obvious unhealthy 8 traits. when healthy, 8s use that inferior Fi to direct their Te or SeTi towards healthy causes (ie: magnanimous).
So i may not ever be able to convince you of the idea that 8s are inferior Fi people... but if you do ever come over to my side, then you will see how ridiculous type 8 ENFP, INFJ etc sounds.
(type 8 ESTP i could definitely see having a form of inferior Fi)