*Facepalm at self* He doesn't, does he? I just saw 'copy' and didn't look back. Sorry
Nice to know that the comment wasn't total garbage, even if none of the good creatures actually came from Amonkhet. (I agree with your choices by the way, don't mean to sound bitter.)
In an an attempt to preserve some dignity, I'll point out that Volrath doesn't actually demand a -1/-1 counter specifically (I think... my track record at reading the card isn't great);
Isareth the Awakener was the first to spring to my mind, but
Heroes' Bane could be very scary indeed, and I believe copying
Grimgrin, Corpse-Born lets Volrath untap normally, still
zap enemies on the attack, have psuedo-vigilance and buff himself. Also, while
The Mimeoplasm is generally used as the commander rather than a supporter, it puts counters on itself, is in colour, generally strong and lets Volrath copy a nice critter that died before you wanted it to.