I like Auron for all the usual reasons that he is a cool bad-ass character with some great lines, predictable I know. He's also a pretty good fighter, though I wish they'd made him a bit speedier sometimes.

Still I think outlaw's point that he could have said more holds up. What about all the summoners who may have died pointlessly in the ten years that he kept schtum? He does seem to delight in being mysterious for its own sake when telling the truth might have worked better. The Yevon priesthood made it easy for him by outlawing Yuna's party, so that they were ready to doubt everything they'd been taught. Otherwise they might even have listened to Yunalesca.