One way in which to take a strong position and yet still present your belief that he has both elements is to state that he is a "flawed" character. You could say "flawed hero" or "flawed villian", etc.. In this situation, you would prove that although he has all the characteristics of a hero/villian, there are certain characteristics that prevent him from fulfilling that role.
If your prompt is to take a position on Ike, you should probably choose whether he is a good or bad character. Decide which way you feel strongest. For instance, if you argue that Ike is sticking to his convictions, show examples of how. Turning his back on his inheritance, and choosing to live a simple life without material wealth.
In anticipating the counter-argument, you can bring up the instances that you find Ike in the wrong.
Faulkner's entire body of work hinges on Ike. Ike is the fulcrum around which tragedy becomes comedy.
Ike is the epic hero in the epic that is Faulkner's body of work, and as with all epic heros Ike is flawed.
When Ike goes into the woods to find the bear he is making the hero's descent into the underworld. Just like Achilles, just like Odysseus. And, like the other heros before him, he leaves his earthly possesions behind.
One cannot meet the gods in this, time and place. The metaphysical is where the gods live and there is no time and place. And the bear is a god. He is one of the old gods.
When Ike comes out of the woods, he is changed. Faulkner is changed, Yoknapatawpha is changed.
The liminal experience Ike has when meeting the bear is the threshold between tragedy and comedy in Faulkner's body of work.
I've often felt that Faulkner's characters exist only in a philosophical sense; they don't always exist as real distinguishable people, in the way that for instance Styron's characters are so delineated. Look at Absalom, Absalom for instance; all the characters talk the same way, are indistinguishable except by their actions, and the motivations are often concealed to the point of being inextractable. These aren't books about characters, or people, but they're books about people dwarfed by a world; they're books maybe more accurately about the world itself. The characters take second place to the world, and the ideas presented by conditions of the environment.