Back when Numenera was still just a Kickstarter project, Monte Cook started hyping up his biggest idea yet, the notion that a character could be described by, even built from, a Sentence. The Dude that does the Thing with That Other thing.
You know: I am a Half-Orc Samurai who Fights Duelling Style...
...oh, wait, that's my last D&D character.
Lets try something from the Invisible Sun RPG instead.
I am a Phlegmatic Order of the Vance who Understands the Words.
Dressed up in mis-applied fancy talk (in the abusive fashion of the Invisible Sun RPG) that certainly sounds nice, but honestly its rubbed me the wrong way ever since the Numenera days. And I think I finally worked out the single biggest flaw.
See, I do think its a clever idea, though as evidenced by my first example, not nearly so clever as it was presented. Players have always reduced their characters down to a few identifiable elements as a short hand to talk with other players. The exact information presented varies depending on the conversation and the exact game being played.
Boiled down to its essence, the problem with the Cook Idea is that his sentences are both Limiting and Reductive. Rather than expanding your horizons, or making deeper and richer characters, you wind up smaller and less interesting as a result.
Lets go back to my D&D character. Without the Cook Idea, the sentence could just as easily be 'I'm a 3rd Level Half-Orc Samurai with the Sword of Kas' (Note: I do not have the Sword of Kas…). Or I could be a Lawful Good Samurai, or a Half Orc Fighter with a Katana, or the Fighter who Fights with His Persuasion Skill...
I can shape that sentence however I like to convey information as needed. Its a bit of hyperbole to suggest the number of sentences I can create about/from a single character are infinite, but certainly they are broader than the single, fixed format suggested by Cook.
But its also reductive. Looking at a single character there are only so many ways I can actually describe my singular character, certainly, but taken from the broader context of D&D as a whole, the number of possible 'setences' I can create approaches the infinite in truth... and not merely because I have far more choices than a mere simple sentence allows for.
Take again the Cook Sentence, which in the Cypher System, and in Invisible Sun, you end your sentence with some 'big flash thing' that goes beyond the basics of race and class. In Invisible Sun this is your Forte, and Monte Cook provides some twenty or so Fortes.
And that is it. Sure, they are all colorful and exotic. Bears an Orb, fuses Fist and Nightmare, Shepards the Mind... one might honestly suggest your Forte is far more colorful and interesting than the means by which you make magic (Your Order).
But it requires Monte Cook to have dreamed it up for you. More absolutely in Invisible Sun than the equivalent in the Cypher system, as you need a solid ten powers arranged in a leveled tree, which is beyond the scope of your typical homebrew rules.
But again: Look to D&D. My equivalent 'forte' might be the specific fighting style I prefer, or a prominent magic item (one of several I bear), or even a choice spell-metamagic combo I use a lot. When the unique thing that separates my fighter from another fighter is taken from the character, rather than used to create the character, the options are much more open, and can change.
Looking at some of the Fortes in Invisible Sun the question I wound up with was 'what if my character joins that cult during game play? Why wouldn't they then have two fortes?', which is an unnecessary question to create. By going backwards, by creating the description before the character, you create a series of rules that can conflict with organic, evolving characters who change and grow, eventually necessitating additional rules to patch the problems created by working backwards in the first place.
Forgive me if you are all five years ahead of me on figuring this out...