User blog comment:ImperiexSeed/The oldest being, archangel or leviathan?/@comment-77.103.230.159-20120512163755/@comment-77.103.230.159-20120515150348

"No. Angel's powers come from Heaven, outside of them, so it's possible to interfere with. Archangels' powers are intrinsic - they are entirely self-contained beings, relying on nothing for survival or power"

Cass at the time had no power from Heaven cause he was cut off hence why he was using souls to power him up but he still had basic angelic powers without Heaven.

"I sincerely doubt Eve was a Leviathan as I can think of many notable differences between them to suggest otherwise. However, I am opened to the possibilty that she indeed had at least some relation to the Leviathans based on the Alpha Vampire and Edgar's altercation"

I would love it to turn out that Dick created Eve and that she was his "Daughter" all along