question is: in a self-insertion fic, has anyone ever cast themselves
as the bad guy/antagonist, and not as a living power battery/new-and-
most-powerful team member/love interest?

  If it counts as a SI, I wrote "The World's Worst Ranma Fanfic!" where 
God (read: me, the writer, who effecively IS God (or should I say 'Great 
Maker,' which makes much more sense) in his/her own worlds he/she 
creates) plays favorites and kills several characters at the same time 
by typing out what happens to them. 
  It's really stupid, but then, that's why it's "The World's Worst Ranma 
Fanfic!" Only I would be so bold (or is it stupid?) as to make such a 
claim...! 

End Shameless Plug. 
----------------------------------------------------------
General Sea Clamp: "And I have arranged for a covert operative-- you 
know the one. He has been given our secretly developed Transwarp 
crusier. He will trace the Transwarp wave back to its source."
General Ramhorn: "If Megatron is found still operating his own agenda, 
what are the agent's instructions?"
General Cicadacon: "Terminate, with EXTREME prejudice."

"Decepticons FOREVER!!" --Ravage, former Decepticon
"You've gotten tricker since last time. I LIKE THAT!!"--Rampage
"If you go to Z'ha'dum, you will die." --Kosh, Babylon 5
"Master! You mustn't! People are watching!!"--Cherry, Saber Marionette J

--Razorclaw X
Author: "Wheel of Fire" and "The World's Worst Ranma Fanfic!"
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