all buffs stack. If you have doubts about abilities stacking or who they stack on, just look at the little buff symbols appearing at the beginning of battle. When you are not sure bring a friend, battle some kakashi clones and watch those little buff animations!

What have you been smoking?? Konan's buff stacks if you have multiple Konans, like killer bee, Great ninja war Ino or any ninja that has a passive that uses a number in its description. If an abillity says it will buff 6 ninjas it will buff 6 ninjas and if you have multiple ninjas with the same passive they all apply. Now, on the off chance you have tested multiple Konans and only one applies buffs, then its a very much a huge bug and it needs to be reported immediately.