Does Grasp of the Undying needs a nerf?

Everybody complaining how is strong but one of the main reasons why he is strong now is his synergy with masteries. Mainly this one. It allows him to sustain way better than he already sustains, and also adds even more magic damage to his kit, as if he didn't already have so much magic damage, allowing him to become super difficult to itemize against (if you build MR, he has a lot of physical damage due to his E)

I am saying that because I've just faced a with Grasp of the Undying. It is scary how much dueling power he has with Grasp of the Undying now. This mastery is essentially Shen's passive combined with a empowered version of his Q. I've been hit by one taunt and half of my healthbar was gone and Shen instantly sustained all damage I did to him. I initially was asking myself how it was possible, but then I realized that this was due to Grasp of the Undying.

Just think of how many champions have such fantastic synergy with Grasp of the Undying. For example, Darius, or Nasus, or Irelia. Masteries are good but currently people are still trying to learn how they work, and I wonder if it's Grasp of the Undying is balanced, or it's people that didn't realized yet how broken this mastery is.

I fear that this mastery is too powerful and simply has a lot of synergy with many champions. If we realize that on the future and Riot has to nerf this mastery, it may be too late, because Riot may have already nerfed all the champions who have synergy with this mastery. And you know what happens when Riot nerfs a champion then nerfs the item/mastery that was making such champion broken.