Imagine that a Shard has, essentially, a battery of "potential" investiture. This is what we think of as the Shard's power. The Shard or its delgates can use this battery to transform the "potential" investiture into "kinetic" investiture which effects a spiritual change, manifesting itself in the other realms. This is "ends positive" investiture.
Now I realize it is commonly accepted that spent investiture eventually returns to the Shard, which I submit might happen if the spiritual change were to be reversed. However WoB says that investiture obeys its own form of thermodynamics, and entropy always increases and no process is 100% efficient. So at least some of that investiture is lost to the inexorable march of entropy and the battery must be recharged...
Now imagine that Adonalsium obeyed the same rules and did, in fact, require a continuous supply of investiture to recharge its spiritual battery. That sounds like a pretty toothless "god."
Well, not to fear good Realmaticists, we can still have the power of creation at our fingertips, this is but a minor setback!
The planet of Yolen was filled with a *nearly* limitless supply of the spark of life, all the creators of Adonalsium had to do was take it. And take it they did. They took and took and took until the entire planet was covered in Fain Life, stripped of its very soul.
In desperation a small band of unlikely allies attempted to destroy Adonalsium to stop the destruction once and for all. They failed. Instead they were forced to use the shattered remnants of its power to take the survivors of Yolen and flee across the void of space, never to use their abilities again.
But the Shards grew intents that overpowered the wills of their creators, and the horror caused by Adonalsium's spawn continues across the spiritual realm where time and space know no bounds. One day, sooner or later, it will come for us all.