Long time, no post! I have been following the deck even though I haven't posted in a long time. :S You wanted a bit of feedback on the Justice sketch - I think it's a fantastic idea and a great composition. I much prefer it to the original sketch on the deck's site, even though that sketch perhaps looked more like a traditional Justice card. I'm working on my own deck (although I'm not posting it on here) and I think some of the best ideas are where you take a few liberties with the traditional imagery. When I saw the first sketch ages ago, I thought "Neville's a funny choice for Justice..." until I read your explanation, whereas with this second version it instantly clicked, since it depicts the moment where karma comes full circle and Neville, the bullied boy, becomes a hero.
For that reason depicting Nagini definitely gets a thumbs-up, but if you're worried about it being a bit gory I would go by the same rules that film classifiers go by. It can still be suitable for all audiences as long as there isn't visible blood and gore. I think if it's kept clean like in the sketch no-one should have a problem with it.
Finally I think I prefer Neville without the robe. Although I don't have a clear picture of Neville's facial features in my head, I would say he looks a bit older than 18 in the sketch. Other than that I don't see any issues with it at all! Well done on all the cards so far, I love them all!
Topsy
I feel the same way and I do prefer it just a bit more without the robe.