Possibilities:Yep. That sort of begs the question, though, just how did they get enough power to break the sphere if they have no worshippers or power there? They were gone for thousands of years.
- They weren't true gods (they may have been once, but aren't anymore) and therefore weren't dependent on worship for power.
- They used psionic power, tapping into the minds of everyone on the planet to draw it directly from them.
- They gathered worshipers from elsewhere and brought them with them or else managed to have a battery to store the worship-energy from before.
- They sacrificed themselves for the power.
- They sacrificed other gods for the power.
- They used an artifact of unimaginable strength, which may still exist somewhere--possibly within the black hole.
- Crystal spheres are like diamonds--hard and seemingly indestructible, but there's a weak spot that if you hit just right, the whole thing breaks. These gods knew where that weak spot is and didn't need as much power as it would otherwise seem.
- The sphere was breaking anyway; the gods just took credit.
- It was an accident; they were attempting to create a ginormous gate so they could draw the population/planet/system into an Alternate Prime. Instead, they created a black hole and cracked the sphere.