@ Riot: Please do not change Grasp to benefit another class besides Tanks and Juggernauts.
I mean seriously both of these classes have virtually no keystone available to them outside of Grasp and Aftershock and by making Grasp proc adaptive damage, something these classes benefit very little from, you are creating less diversity for a single class in favor of others.
We have already seen what happens when intended fighter/divers/assassins can do when they are allowed to build tanky with little to no trade off in damage. Tank Yassuo, Ekko anyone?

are built on a lot of Fighters and Divers currently. Fine they may not have as much health to make the adaptive damage as high as a pure tank but they can stick to targets with their mobility and keep the proc going due to inbuilt AS steroids, abilities that scale well with AD or items they typically purchase that give them both AD and AS. Thus they can keep the damage going all while healing and ramping up in damage not only making them almost impossible to kill but not be killed yourself.
If tanks and other bruisers, like juggernauts, are too strong with Grasp then have it ramp up slower with the larger returns coming mid game. this will cut down on them being too beefy early as well as lane dominant early. Please do not kill this keystone as it one of a rare few currently viable for my favorite classes.
. I currently do not know of any Bruiser that is taking Grasp.