Bond of stone is ok imo
I get that people want this replaced because it doesn't feel as game changing or lacks visibility compared to other masteries like COTC, TL, or even Grasp. However, just because a mastery works in a more passive way doesn't make it a bad mastery. As it is right now BOS fills a very specific niche that I think is a healthy niche to have. Perhaps the mastery shold be reworked so it doesn't take a keystone slot and instead is a basic mastery but I for one would like to see BOS stay in the game and continue to fill it's niche.