An argument like this would have to be intrinsically allowed to assume the major tenants of ECT (Hell exists, the punishment is eternal, the punishment is conscious, and the punishment is torment) as true.

In this situation, we are avoiding “would be” or “could be”–we want definitives: is God evil, or is He not?
The exception, of course, is if one were to argue that God would only be evil in that instance, but would not necessarially be evil forever. But, considering the unchanging nature of God that most accept, it would seem that most would not argue this.
However, it would be good if a user came in and added that for clarity: God does not change, so if His action is ever evil, He is evil.