Disclaimer, I love the kineticist to bits... it's easily my favorite class (I hate 1/day resources and the "is this dimension door going to be more useful later, or should I use it now", but I still like fantastical bits to my characters).
The void element can do darkness quite well. Dreams and illusions are a bit harder. You can use the "Kinetic Invocation" feat to get at will silent image. And there are some other interesting misty things that should fit well enough.
You'd have to choose either water for the dreamy bits, or void for the darkness bits first, and then take the other at 7.
I'd probably go void (gravity blast), water (cold blast) at 7th, then probably water again at 15 for ice, or maybe aether for freaky manipulation of stuff and invisibility. Since your primary attack is physical, tons of DEX is obviously a requirement, so you can hit things.
Like most kineticists, it should be pretty viable. (I'd avoid the negative energy infusion until much later, because you'll be in trouble against undead/constructs, which are super common).
Actually... I really want to play one now...
