Power Stone Chance
When a base is destroyed, you have a 25% chance that the Headquarters will give you a Power Stone.
Every other building on the base has a 2% chance that it will give you a Power Stone.
If you do get a Power Stone from a building, there is an 85% chance it will be a Fragment,
12% chance it will be a Shard, and a 3% chance it will be a Crystal.
A particular type of Dark Statue boosts Power Stone chances.
The extra percentage of chance that the statue gives is multiplied with each building's base chance.
For example,
if you have a total of +100% Power Stone chance from statues, the Headquarters has a 50% chance of giving a Power Stone,
and every other building has a 4% chance.
You will always get atleast one Power Stone from Dr. Terror levels,
and Lt. Hammerman levels always give a predefined set of Power Stones.
The above chances do apply to these levels, however.
You CAN get more Power Stones in addition to the guaranteed ones.