User blog comment:IamJakuhoRaikoben/Chapter 405: Tartarus Arc: Part 6 - Magna Carta, Review./@comment-25405856-20141020202006/@comment-5303512-20141020223149

I imagine the voice for Acnologia will be either the voice actors of:

1. Deathwing

2. Smaug

3. Alduin (Skyrim)