A: The same. B: The same but doesn't get wounded. C: The same but doesn't die. D: The same but doesn't get kidnapped. E: The same but doesn't get kidnapped. F: The same but doesn't die. He tries to spell "FF" (short for friend forever). G: The same. H: The same as Dutch but gets covered in goop. I: A bully with the design of @AlfabetonsOfficial's Portuguese Y. Like the other bullies, she doesn't leave the group. Owns the slash gem. J: Equivalent of LHDA N. K: Equivalent of ALBTWIAIOF R but loses his gem in episode Z after getting taken by F's goop. L: Equivalent of LHDA Ñ but doesn't die. Owns the tilde gem. M: The same. N: Equivalent of L but doesn't leave the group. O: The same but doesn't leave the group. P: The same but doesn't die. Q: The same as @wario100's LHDA version of ALBTWIAIOF version 2 but doesn't get wounded. R: A bully with the design of @AlfabetonsOfficial's Greek Ξ but doesn't leave the group. Owns the hyphen gem. S: The same as ALBTWIAIOF but doesn't die. T: The same but gets freed and joins the group. U: The same. V: The same but doesn't leave the group. W: The same as LHDA but doesn't leave the group. X: The same but fully lavender and doesn't die. He also gets covered in goop. Y: The same but fully yellow and gets covered in goop. Z: Y's brother who has a similar relationship with X to what G and S have. He comforts X and Y after X loses his gem, and also gets covered in goop. There is no Q equivalent because F cries the question mark gem in his cave and puts it in a chest, which he opens after freeing the other letters from his goop. There is no W equivalent because there is no N equivalent, and therefore no nightmare. There is still a coward equivalent, that is shown in the flashback. There is no Z equivalent because the letters live on a normal spherical planet. In the epilogue, titled "Next Time Won't You Sing With Me" due to the flashback episode being "Now I Know My ABC's", there is no gem to reverse time or heal everyone because everyone is already okay (minus the goop, which F just licks off). I will explain why there is no N equivalent inside this project.
Credit to everyone, especially @AlfabetonsOfficial for the bases of H, I, J, R, and W, for the bases of K, L, N, Q, S, X, Y, and Z, for the sprites, and Mike Salcedo for Alphabet Lore.