To make a campaign villain more memorable, give him a one colorful detail. Like red face, or 6 fingers on the right hand, or a peg leg, or a T-shirt with an insult to a party member. If you're out of ideas, just make your villain fat. This shall make bigger impact when the party meets the villain again later in the campaign.
Of course, if you make the villain fat, there's also the option of keeping it a surprise until the end, lest you run into this problem (courtesy of Ultimate Spider-Man).
Just imagine giving a whole party enough time to make flash cards full of insults.
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