joshuazucker// Thanks for enjoy our Sudokus.
Weighted Killer(Spoiler!!) : See http://home.postech.ac.kr/~meso/sudoku/weighted_killer.html
When I made this problem, Kwaka found that solution route very quickly. That's why we give (relatively) low points on this hard problem. Sorry for that
Once you add the cages at two bottom rows(with additional cell R7C8), then you can get the clue. Since R8C5 and R8C6 can not be both 1 at the same time, the sum 96 is the minimum possible value. Hence R9C1 = R7C8 = 1 and we have a multiple set {R8C5, R8C6} = {1,2}. That is the starting point I intended. If it is not enough, the sum of first row also gives you many informations.