Sand Man vs Spiderman vs Goblin

Sandman is a criminal that actually murdered uncle Ben in the first movie (the robber didn't do it) and he escapes from prison (or is let out) and stumbles onto a government testing site and he walks in an experiment with sand and his molecules or something are replaced with sand. Now he can become and control sand. The black suit spiderman wears is a symbiote from space. It enlarges his powers, but makes his darker side come out (he is more agressive and such). After he gets rid of the black suit, it attaches to Eddie Brock, who then becomes Venom.

I know the story of spiderman 3.There's a black element which comes from space and hits spidermannow he becomes villanious and now the fight lies within and he has to defeat himself.I can bet you that this plot is right.You will come to know after you watch the movie.