"Tōmyz dāryssy keso oktiot umāzisi."

Translation: Five kings are coming to this city.

[ReinerSelb]

tōmys... "d" is neither a vowel nor a voiced consonant. see http://wiki.dothraki.org/High_Valyrian_Adjectives#Class_I + notes [7].

[Nngpi]

'D' is pretty much the definition of a voiced consonant. It's impossible to properly pronounce an 's' (unvoiced) right before it, that's why it turns into a 'z' (voiced). 'T' would be the unvoiced one, so if the sentence went 'five teachers ...', it would be 'tōmys tentyssy'.

[Leranio]

Shouldn't it be "kesot oktiot"? See http://wiki.dothraki.org/High_Valyrian_Adjectives#Class_I notes [8] : "The -t is omitted before a consonant, but retained before a vowel." "Oktiot" begins with a vowel.