Help: Likeness used in comic
artisdifficult.wordpress.com
artisdifficult.wordpress.com
Parody can be fair use (http://www.law.cornell.edu/uscode/17/107.html; caution annoying interstitial) and protected internationally I gather but is not always. The original costume probably could pass as a parody (or be deemed personal use) and so be fair use whilst this comic-book image doesn't look parodical it's just a commercially used derivative in a different media.
Adaptations of other's work (that use a "substantial part") are not allowed without permission of the original creator.
Tracings? You think it's OK to duplicate someone else's copyright work as long as you trace it? That's almost the definition of a slavish copy - like considering copy-pasting the binary presentation of an MP3 to circumvent the creators rights.
Marvel are presumably distributing this internationally? Remember that fair use is a lot narrower in some non-USA jurisdictions.
Lastly, is the owner of the convention photo copyright sure that this is a copy of his image. Presumably others could have taken pictures of this guy at the same time?
You feel happy and thrilled that someone used something yours in something good, but you are afraid that you are sucker for feeling that because course of action that is touted as moral and right is to sue their asses.
That said, I would look definitely look at this as an opportunity to make contacts, get work, etc.
As a side note, you countered their rip off by taking a whole page out of their book and putting it on your website. Just saying.
He's not only using an excerpt of substantially reduced quality but also reporting and/or critiquing the work. Lastly the work he's critiquing is in part a derivative of his own work and so the presentation of at least that derivative [half-page] image could not be a copyright infringement IMO unless he'd licensed away the right to duplicate it (this would not be true if it was transformative).
Realistically it's not in your interest to sue them - the upfront costs and risk of losing would outweigh the likely financial benefit.
That said, I might drop them an e-mail pointing out the similarities, including the two images, say you're a fan and you're not looking for money but perhaps ask for a signed copy of the comic or whatever as a thank you.
If they don't get back to you or get all shouty then you let it go and you've still got a good story to tell. If they do then maybe you get a signed comic book and a good story to tell.
http://weeklyrot.files.wordpress.com/2009/04/wolverine14.jpg
They do something cool and put you-dressed-as-Wolverine in a comic book, which doesn't make them any money or cost you any money in any way, shape, or form. There's no damages. And it's something pretty cool you can show your friends.
And your inclination is to... sue them?
Strange world.
It comes down to what you want to do. Do you want to be a fan (blown-up of the page) or do you want money (and to tear down the company that makes something I gather you like)
If it was me, it would hinge on whether I liked the company. I mean, if my favorite company in the world infringed on me, I would absolutely not sue them for a billion dollars and destroy something I loved.
edit: if you wanted damages you would have to be able to prove irrefutably that your picture is authentic and predates the comic. And I mean, irrefutably. If proof of the date it was taken relies upon the date of the convention for example, you had better be able to prove without a doubt this picture was taken at the convention.