Bond of Stone is in need of a SERIOUS touch up.
With masteries adding so much additional damage, whether it be 2% increased ability damage, 3% increased overall damage (new double edge sword), 2% increased dmg when no allies are nearbye (assassin), 5% increased damage to targets below 40% health, etc etc. Bond of stones wimpy 4% dmg reduction is extremely shitty. Consider this, why bother taking bond of stone, if it gives you 4% increased effective health say, when at 3000 health that's roughly 120 addional health worth of dmg you can recieve. Why do that when you could have much more, up to 300 addional health from the other keystone in that tree, and then get sustained health upon minions dying by you?!