I would look at the Mace mastery powers from the ATs to get an idea of what powers are availiable.
Other than that, he's a Brute. While I'm note positive, I'd peg him as a Energy Aura secondary since his pool powers are similair defense shields. To make an educated guess, Super Strength or Energy Melee could be a likely primary.
My advice is to not worry about it too much. I'd focus on making a story with decent writing with solid character development and plots. Researching what Black Scorpions power might be is well and good, but don't get hanged on being exact.
I don't know how long a posted story can be, but if 30+pages is too long just post a link instead.
Black Scorpion is a Super Strength / ??? Brute.
None of the Villain Patrons really fit into any one category.
Mako, for instance, comes off as a Brute type, too, but he also has strong leanings into the Stalker Class. Scirrocco is apparently a Corrupter, but he also has leanings to the Stalker class, and Ghost Widow is obviously mainly a Dominator-type, but she has nifty little toys no player seems to have access to...
Black Scorpion always strikes me as a blend of a Brute and a Corrupter. Heavy armor and heavy ranged weaponry with a couple melee attacks for backup. An exceptionally dangerous combination.
Paragonwiki has his powers listed pretty clearly.
My Stories
Look at that. A full-grown woman pulling off pigtails. Her crazy is off the charts.
Well, for the story, just try putting about 20 - 30 pages worth on each post. No need to post a link. 
Black Scorpian is my hero- Er, villain... >_>
If you are going to post a story here I suggest one chapter per post. There are no limits. I have a 120 (If I remember correctly) MS word story on the boards in my sig. But make sure you seperate your paragraphs so it is easy to read. A lot of people forget to do that when transferring.
Mainly I need to know what the Black Scorpions power sets are. Does he have any special attacks?
Also, how long can a posted story be? I've been writing one, and its turning out REALLY long, it'll probably end up being around 30 pages on microsoft word, thats single space, size 10 font.