Psi and/or magical powers, if real, are nearly useless.
It is a cardinal sin to bore the reader.
Consider the true picture. Think of myriads of tiny bubbles, very sparsely scattered, rising through a vast black sea. We rule some of the bubbles. Of the waters we know nothing.
I love superconductors.
The witnessing of titanic events is always dangerous, usually painful, and often fatal.
One mark of a good officer, he remembered, was the ability to make quick decisions. If they happen to be right, so much the better.