That sounds AMAZING and I'd like to refine it a bit more. On reddit you could see karma breakdown by subreddit which was useful to see where people were most active. So what about:
total karma up to say 5000 or so
percent breakdown of total karma by magazine
So if you have say 10,000 karma from kbinMeta and 5000 karma from all other magazines combined it says like reputation: 5000+ and then breakdown: kbinMeta - 67%, askKbin - 10%, etc etc