"Venom is NOT Eddie Brock, our goal was to tell an original story."
Well it has to be someone with a personal reason to hate Spider-Man so they'll model the appearance and powers after him. It COULD be Doc Ock I suppose, getting revenge for having his arms taken and being "trapped in this USELESS body".
Most likely answer is it'll be Norman as if Harry dies (weather it's actually their fault or not) he'll want to take it out on the Spider-Men. Suppose there's a chance it could be Harry himself if they (stupidly) try to use the symbiote to save his life but, unless his father dies, I don't see what reason he has to hate Spider-Man.
I DOUBT it'll be Kraven, doesn't seem the type to want that sort of thing, or even get that mad about Spider-Man not dying. If anything the challenge is what he wants.
Of course I'm thinking characters connected to Peter when it could (though most likely wont) be someone connected to Miles. Though I haven't played the Miles game yet so I don't know if anyone there has a particularly potent grudge on him.