A few others have subsequently touched upon this.
I believe Nash is/was the Clairvoyant and is playing the long con here to completely throw
everyone off his tail. While he's currently "dead", I'm thinking Ward shooting him was part of the plan all along and he's counting on his team procuring/solving the GH235 mystery so he can be resurrected. (Out there side theory, but Nash --> MODOK? I know MODOK's more associated with AIM in the comics, but I'll happily accept him being HYDRA-aligned instead.)
So basically, we know that the Clairvoyant is primarily interested in the following:
* Building a super soldier army.
* The GH235 serum, which will revive him, and subsequently any of his fallen troops.
* Whatever Skye turns out to be.
* Assorted powerful weird-science goodies, courtesy of SHIELD, Quinn, aliens and whoever else.
Looks like a pretty solid world domination scheme to me.