Because a quick glance through this thread showed me that most of my obscure choices were taken, I'm going to try none other than our own Yahtzee.
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No fucking way! This thing is the fucking HAL 9000. GLaDOS doesn't have shit on this guy.
OK, let's try something new.
How about...
Hank J. Wimbleton from the Madness Combat series.
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Holy shit! I can't fucking believe it! How is that even possible?!?!
All right, one last try. I've got it! Keyboard cat! There's no way this doom machine could get this one right!
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15 guesses! 15 fucking guesses! This thing is surely the Antichrist, lulling us into a false sense of security by using its near omniscience and omnipotence to amuse us. I'm onto your scheme, Akinator, and I'm going to prepare!!!