#1 reason: he looks like several things in my nightmares. Also:
He's arrogant (but so are many other characters). Something about his demanding ungodly amounts of gil to help Summoners sacrifice themselves for the good of all Spira and his own glory bugged me.
His Aeon has no face.
The bird mask reminds me of Tash or something. It's predatory. It wants to PECK OUT MY EYES.
His Summoning music is creepy weird.
Lady Ginnem died trying to get him, and Lulu obviously had not much fun at all in that cave, so my overprotective streak pops out.
I got him too near the end of FFX to use him for anything, so I only ever wound up fighting him.
MY GODS THE DARK AEON IS HORRIBLE HORRIBLE!
I just spent a good half hour fighting Even More Evil Yojimbo for the first time ever, and we held our own for a long time, using potions and phoenixes and hanging on by every toenail, but that Zanmato coupled with the nasssssssty little doggie finally took down everyone at once, including Paine. That's the first time I've died in X-2.
Sorry, Lu and Auron, we'll have to try and avenge you again on another pass. YIKES.
I probably tackled it too soon. I just started Chapter 3, went to Besaid to help Lulu and Wakka (of course) and then made a beeline for the Cavern of the Stolen Fayth, because I had a strong hunch that Icky Icky Creepy Aeon would be lurking in there somewhere.
I was right.
*crawls off in a corner to shiver appreciatively*
That's actually the first bit of this game I really enjoyed with all my heart -- it was just the right mix of adrenalin, fear, anger, weirdness, beauty, and angst. I felt like a wee little beastie bravely defending myself and my nest-mates against the Evil Whatsit.
My reaction makes no sense whatseover, but then, it makes no sense for people to enjoy horror movies that genuinely freak them out.
I wonder if there is any way to beat the thing with the stats I've got right now. I'll have to ponder strategy. Also a good thing. I so much prefer fights that require a bit of strategy, and so far, I haven't been in anything in X-2 besides Sphere Break that required anything more than quick reflexes.