use '?' for JOKER (blank)

From letters O, B, F, U, S, C, A, T, I, O, N  I made following words

11 letter words

obfuscation[18]

8 letter words

factions[13], factious[13], subtonic[12], boniatos[10], auctions[10], cautions[10]

7 letter words

confabs[14], faction[12], confits[12], bonacis[11], bosonic[11], botanic[11], cobnuts[11], fustian[10], boniato[9], bastion[9], bonitas[9], obtains[9], actions[9], atonics[9], cations[9], bonitos[9], acinous[9], niobous[9], auction[9], caution[9], conatus[9], toucans[9], suction[9], boutons[9]

6 letter words

confab[13], fincas[11], fiasco[11], confit[11], fustic[11], bonaci[10], cabins[10], cobias[10], bacons[10], bancos[10], binocs[10], buncos[10], cobnut[10], sacbut[10], bustic[10], cubist[10], cubits[10], foison[9], faints[9], fusain[9], fusion[9], unfits[9], founts[9], futons[9], basion[8], bonsai[8], casino[8], bonita[8], obtain[8], action[8], atonic[8], cation[8], bonito[8], actins[8], antics[8], nastic[8], biotas[8], coatis[8], scotia[8], batons[8], cantos[8], cotans[8], octans[8], bionts[8], tocsin[8], tonics[8], taboos[8], oboist[8], boston[8], contos[8], nostoc[8], nubias[8], acinus[8], cousin[8], tunica[8], toucan[8], bouton[8], tabuns[8], cantus[8], uncast[8], cutins[8], tunics[8], subito[8], coitus[8], counts[8], tauons[6], outsin[6]

5 letter words

finca[10], coifs[10], coofs[10], facts[10], cuifs[10], ficus[10], focus[10], cabin[9], cobia[9], bacon[9], banco[9], basic[9], bunco[9], scuba[9], cubit[9], naifs[8], fanos[8], finos[8], foins[8], infos[8], faint[8], afoot[8], fiats[8], fatso[8], softa[8], foist[8], fonts[8], foots[8], fauns[8], snafu[8], aboon[7], basin[7], nabis[7], sabin[7], cains[7], obias[7], canso[7], bison[7], cions[7], coins[7], icons[7], scion[7], sonic[7], boons[7], boson[7], coons[7], actin[7], antic[7], biota[7], coati[7], baton[7], canto[7], cotan[7], octan[7], biont[7], ontic[7], tonic[7], taboo[7], conto[7], baits[7], canst[7], cants[7], scant[7], bints[7], boast[7], boats[7], botas[7], sabot[7], ascot[7], coast[7], coats[7], costa[7], tacos[7], obits[7], stoic[7], boost[7], boots[7], coots[7], scoot[7], nubia[7], uncia[7], bunas[7], incus[7], bonus[7], bosun[7], conus[7], uncos[7], tabun[7], cutin[7], tunic[7], antis[5], saint[5], satin[5], stain[5], tains[5], iotas[5], ostia[5], stoai[5], santo[5], snoot[5], toons[5], unais[5]