Man ‘Judas Unchained’ sounds like a real familiar title but the synopsis does not right any bells.
I think the artifact that could be tuned to pull power from celestial bodies was sold to the human / or traded or gambled or something - by an alien entity named ‘wheeler’ maybe?
The protagonist had a friend named Zero or Zeno that was kind of a techno mystic?
Idk my memories are pretty spotty
The book is Signal to Noise and its sequel A Signal Shattered by Eric S. Nylund.
A personal favorite of mine! Wheeler is such a convincing villain, and the existence of such a character as an explanation of the Fermi paradox is eminently believable.