I think the problem with Raphael is
how he is introduced and inserted into the current narrative.
The entire scene just feels those random extra sequences that movies add in so they can add it to a trailer to say "and we've got devils too!"
He enters the narrative with little to no introduction or foreshadowing, and worst of all, completely abandons it immediately after. It feels totally random as there's no clear cause and effect for him showing up (i.e. if he had shown up due to the player tampering with the soul coin, etc, that would make more sense). There are also serious tonal issues with the scene, since it feels like the developers are genuinely trying to surprise the player. However, Raphael's disguise is wax-paper and the transition to the "reveal" happens only seconds later. It's utterly predictable in a hilarious way, but the story seems to want to frame it as serious.
Overall, at this point Raphael feels disconnected to everything else this point - his scene contributes nothing - no new obstacles, no new characters motivations, and no consequences.
This is coming from someone who does not feel like every D&D adventure needs to start slow, mundane, and within a Tavern. I'm perfectly okay with the more high-stakes, cinematic premise that Larian has chosen. HOWEVER, even within that context, Raphael's introduction feels like a DM randomly yelling "If you thought hell, dragon, giths, and mindflayers weren't enough, and now a devil shows up!"
Compare Raphael to a certain character from the Witcher 3 (Spoilers):
Gaunter O'Dimm is a fantastic example of how to properly introduce a Faustian bargain with the devil into the narrative.
Witcher 3 takes the time to introduce both the character and the legend separately in bite size pieces, seeding them both into the player's mind until it all converges into a reveal when it was ready for the narrative spotlight. It serves a purpose in the story because it pays off a series of hints and promises made to the player along the way.
Note, it's not a matter of whether the reveal is surprising or not that makes it good - it's the fact that it feels earned and meaningful.
The delight a player feels with the Gaunter reveal doesn't solely comes from the fact that "I knew it all along", but the fact that "I can't believe these little clues/foreshadowing actually have so much meaning."
