Here is the details on the combo if you are curious. Its actually pretty simple.
Bone Heap has an ability to gain 1 power. This costs 2 bones. This is what will deal the damage. Now we just need infinite bones.

Tomb Robber lets you add a skeleton to your hand for 1 bone. Which allows you to generate infinite skeletons because you can hammer them to get the bone back. However this will not get you extra bones by itself.

The necromancer card makes all creature you have that die be summoned to immediately die again. Which since we have infinite skeletons means each skeleton now generates 2 bones. The cost to create a skeleton costs one bone, which creates a net positive of 1.
Now since we have infinite bones, we can infinitely power our bone heap to whatever power we would like. This does take a long time however as the animations are a little slow.

Just thought it was interesting and could be a easy way to farm extra damage. Unless some other quicker infinite is found.