Like it was mentioned earlier items are what define builds for the most part in Grim Dawn. Some skills from classes look like they could complement each other very well but due to the lack of specific items that bolster that skill combination the idea may not perform very well.
That being said there are some item sets that try to bring the pets, the Arcanist, and the Necromancer together. The Diviner’s comes quite close though it focuses more so on Devestation than on Aether ray. You could still put a point in Aether ray and use it as a complimentary attack.
Grimtools has a superb feature that lets you search the web for saved build links that have been posted across the web. It’s a simple way to see how other people have forged their builds.
Here are some builds that I found:
Crypt Stalker Diviner
Ascendant Diviner
Rattosh Claivoyant
Korvaak Claivoyant
No-set No-pet Green Build
Half-Diviner Green Build
Many of these builds can be outdated and in need of tweaking. Overall I have found that most builds posted are far from optimal so there is always room for improvement when devising your own build or build variant. This is the guide that helped me grasp the fundamentals of creating solid builds. Other than that the only surefire way to test your build is to do it in-game. You can use GrimStash to quickly edit in the characters and items you need.
I think you could perhaps come up with a unique build out of your idea. Maybe the Blight Fiend could be a tool to bolster your offense by decreasing enemy defensive ability and taunting them, allowing you stay still longer. You could also just try focusing on the skeletons and maybe the ray could deal a small amount of damage with one point in it (after all you wouldn’t want to just stand there doing nothing, right?)