So, I tried making a 4 faction BG that isn't simply just split champs, but split spells, relics, and equipment. I made one that totals 15 runes in each of the 4 factions, but it breaks the game. At present, I can only select Forsaken Wastes as a bonus, the other side is blank for all 4 options. With only split champs, I'm able to select from the 4 possible bonuses.
soultap garnet is ud\fs, so split has to consist either ud or fs dreadwood strider is fw\kf, so it should consist fw or kf so it should be: fw\fs, fw\ud, kf\ud or kf\fs. fw\fs = ash the bandit prince is ud\kf fw\ud = tortuns are kf\fs kf\ud = darkmarsh blackstaff is fw\fs kf\fs = defiling spinel is fw\ud So it seems there are problems in this bg in form of impossibility to create 15\15 split. Split has to have 15 runes of one faction and 15 runes of another faction. Nice puzzle though. Numbers below your bg is not the number of runes for each faction (if that would be the case, you would have 60 runes since 15+15+15+15=60), its the number of faction colors your deck has.
