As long as he can wish whatever he wants, why not aim high and go for a cool A grade piece of prime rib (Hurley) instead of a cheap cheeseburger (Alison)?
It's not like Alison't incredible personality, incalculable fortune/inheritance/trust fund or limitless IQ compensated for her lack of physical attractiveness.
I think the Devil would delight in tricking Eliot if he wished for her; however, it would be quite interesting--more intriguing than Alison.
shareBut the hot-bodied form the Devil had taken is not necessarily the one he would have been presented with in Tahiti.
It was towards the end that Elliot and we are shown the big, fiery, "Night on Bald Mountain" form. Would Elliot have been smart enough to even attempt to guarantee the attractive, fun form?
And besides, the message of the film is that you just can't trust the (supposed) Devil, as his intentions are never good.
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The story is king.