Following are a number of back-translations as well as a sample translation for translators of Ezekiel 28:15:

• Kupsabiny: “You did not have any blemish from when you were born until when you came into sin.” (Source: Kupsabiny Back Translation)
• Hiligaynon: “You were blameless in your ways from your birth until later you did wicked-[thing].” (Source: Hiligaynon Back Translation)
• English: “You were completely good in all that you did,
  from the day that you were created/born,
  until you started to do wicked things.” (Source: Translation for Translators)