Ruin Explorer
Legend
Yeah, DPR schmee-PR. It's a limiting way to look at character builds to begin with, and even less useful in this example. No offense meant @Ruin Explorer , I just don't see the importance here. The importance of DPR as a metric rises in direct relation to the importance of combat as en encounter resolution tool. The concept of the Face is, first, a low combat/DPR idea to begin with, and, second, a concept that would only really be considered for a low DPR game anyway. Obviously there's a sliding scale, and there are lots of stops between my position and yours.
What I'm getting at is that if I want to build a face, why would I concern myself with DPR at the cost of the core competencies for the concept I'm building? Assuming for a moment that I had decided that the campaign in question was the correct one to support such a build.
You're making your character rubbish at their secondary job for no actual gain.
That's the problem you and some others don't seem to be actually getting.
What you're proposing does not make you a good Face. At all. I've played a lot of Faces in D&D and other games. In 5E, to be a good Face, without magic getting involved, you want a high CHA (but it doesn't need to crazy), and you want as good of Persuasion, Deception and Insight as you can get (often you have to accept another PC will be making the Insight checks though).
You say DPR doesn't matter. Okay, but nothing about being a Face says you should be using the Help action or anything else you've suggested. That's not a Face thing. That's a support character thing, or a planner/leader thing. Who are different tropes, and often/usually different classes to the Face.
Also there's no such thing as a "low-DPR game". Combat is combat. It doesn't matter if there's a little or a lot. You need to be decent at it in order to not die, unless your DM totally softballs all the combat, which isn't part of the equation that leads to playing a Face. If you are saying "I know my DM will only throw total softball combat at me, so I don't need to be good at combat!", well, okay, that's weird, but okay, and even then Mastermind is not the best choice for a Face.
You haven't actually argued against what I'm saying. Let's make it even clearer, I am saying that, as Rogue, to be a good Face, the MAIN THING you need, is to use your Expertise on Persuasion, Deception, and I would suggest Insight. Make sure your CHA is at least 14 (you can go higher, but there's very little point initially unless you're rolling stats or the like). If you have a way to get 16 CHA and 16 DEX without ridiculously gimping yourself, great. But your first ASI should probably still go in DEX, because the gain from putting it in CHA is smaller than that unless literally you do, every day, all day, is talk to people. Which this being D&D, you don't. You also sneak, stab, fight and so on.
And that's it.
You did it!



You became a good Face as a Rogue. By putting Expertise in three skills. You can put the fourth either in Intimidate (if you also want to be a Scary Face), or something more directly useful, like Perception (as you probably want at least a positive WIS mod for that Insight).
You don't even need a subclass. You are already a good Face. Assuming you have the RP chops to back it up, but we have to assume that.
Mastermind doesn't really give you anything mechanically. Proficiency in some stuff you could well be proficient in anyway, a couple of languages and the accent-imitation trick (which you can certainly do without being a Mastermind, it just might require a check).
At least it's a lot lower-level and easier to use than the Assassin stuff, though that is eventually more powerful (and very similar in function).
Inquisitive doesn't give you much either - Ear for Deceit and Eye for Detail are cute rather than great, and Ear is invalidated by Reliable Talent at 11th.
Soulknife is the best so far - Psi-bolstered Knack is a massive mechanical advantage for a Face, easily outperforming all the stuff we've seen so far outside of hyper-niche situations.
Swashbuckler is strong for a Face, in a couple of ways. The early abilities don't make you a better Face, but they make a Face a better Rogue without sacrificing Face-ness. And Panache is incredibly strong for a Face, who will have Expertise in Persuasion. The out-of-combat effect is particularly nice, as it is one of the rare occasions where just rolling social skills IS in fact, magical!
So if we're talking "who is actually the best Face?", then I think it's clearly going to be the Soulknife. If we're talking about who combines being an extremely good Face with being an extremely good Rogue, including turning backstab into frontstab, then it's Swashbuckler.
It sure as heck isn't a Mastermind who is blowing every action and bonus action to grant single-attack Advantage to his buddies. As I said, Hannibal isn't Face.