Whoops. For some reason I thought Fire Buckler was

5|4. Just looked it up and realized it's

6|4. I'll change this shield to
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6|4 or even
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6|5 in a few hours if there aren't any other comments.
This card is first and foremost designed to be a more entertaining version of

Shield. However, unlike fire shield, your enemy's photons, golems, phoenixes, and deva vus won't usually die instantly - this shield doesn't auto-counter them quite so intensely. OTOH, even your stupid grabbow's stupid quinted Growth creature isn't invincible, which I think is a good thing, because damage shields shouldn't be something creatures can just ignore. Like Thorn Carapace, your creatures are never safe from this shield.
Other versions of the art I am considering:
http://www.sumopaint.com/profile/?id=417367