That's a cool idea to do a work based on an actual game! I'm studying to be an illustrator myself, and I gotta say that the GW artists are waaay too underappreciated! They churn out incredible paintings, that aren't even close to rivaled by any games that I know of. That new Daemonhunters codex painting is awesome! Aaaanyway, back on topic..

Ive had 2 seperate instrances of killling the bloodthirster:
(It seems heroic every time you kill one of them, to think of it)
The first time was when I charged the bloodthirster with 2 scouts. They managed to get 5 wounds(extremely lucky!), and killed him outright.
The second time was when both my army and the chaos army were completely dead except for a Bloodthirster with one wound left and my dreadnought that had had its lascannon arm ripped off. The Bloodthirster charged my dreadnought and totally demolished it. The dreadnought blew up, and the explosion took off the bloodthirster's last wound!:lol It's the first time I've played in a game where it was a flat out draw with not a single model left.

And on the other side of the coin...
My Sanguinary Priest had just plowed through the IG army. He killed an Inquisitor, 3 assassins, and about 30 guardsmen without taking a wound. He consolidated towards the last remaining IG squad of 3 men, but came short by an inch. On the IG turn the 3 little guys with lasguns stood their ground with the gore-covered SP right in their face. They rapid fired their lasguns and managed to kill the Priest who had just demolished the whole IG army! :p I have to admit, I was rooting for them! Unfortunately, they very unheroically died from a Whirlwind rocket the next turn.