So I looked on the wiki and it's interesting how Unsullied conjugates (at least in my opinion).
Nominative: Dovaogēdy (singular), Dovaogēdi (plural)
Accusative: Dovaogēdi (singular), Dovaogēdī (plural)
So Dovaogēdi is both the nominative plural, and the accusative singular :)
Found it by looking for Unsullied here: https://wiki.dothraki.org/High_Valyrian_Vocabulary#D