Well first off, when you're doing your links, you should label them as to what they lead to. You can do this (replace the parenthesis with square brackets and don't use quotes):
(url="the url that you're using")"The label/name of the link"(/url)
Also, you may want to do a separate preview image for each one, and crop them so they can be seen better
Lastly, Thunderstrike has some blank area under his chest, so it looks like he got chopped in half.
Other than that, they're a great start! I look forward to more.