It depends on your definition. He is a person gifted, and cursed, with an extraordinary existence that allows him to both help and hurt humankind to a great degree. He wants to help. By that token, sure, he's a superhero.On the other hand, his powers were given to him for the explicit reason that he is supposed to advance the agenda of the Green, which is the collective energy of all plant life on Earth. Plants and people do not have the same goals, generally, and there's going to be conflict there.
I think Swamp Thing and Superman are two sides of the same coin, but Superman has access to a normal human life, via Clark Kent, that Swamp Thing simply does not. So, while their power levels might be analogous, the way they interact with the world is very different. I tried to make that explicit in #20 so we'll see what people think.
Swamp Thing is a book that has always had a horror component, and Scarecrow ties directly into that, especially the particular reason he and Swamp Thing happen to be in the same spot in #19.I also want to explore a lot of what Swamp Thing is afraid of as he develops his role as the Avatar of the Green, and Scarecrow has always been the classic choice for exploring the inner nightmares of the hero. Swamp Thing #20 gets into that in a big way and I think it's fun.
He also seems to have access to Green powers, although he doesn't seem to use them or fully understand the Green itself in the way Alec does. He's one of your classic "everything I do, I do for the greater good" type bad guys, and those are some of the scariest of all.
For the full interview and further details be sure to read CBR’s interview here.
And for more on Charles Soule and his other works, check out his Q&A with our own Royal Nonesuch here.