>>43329038The Culture, a civilization of OP as fuck AI craftworlds, once found itself at war with a race of super-intelligent, near-immortal, apex predators.
Both sides agreed not to militarize any of the ringworlds in the theater of war (which spanned about a quarter of the entire galaxy).
When the other guys violated the agreement and advanced on a ringworld, this is how the Culture responded:
First, they evacuated the ringworld before the enemy arrived. Then they sent one of their craftworlds--not even a dedicated war machine, just the nearest mobile hab--to the system with the ringworld. When it got there, the craftworld used its forcefields to lay down a pattern of charged antimatter particles to slice the ringworld into slabs. Then it ripped open the fabric of spacetime to liberate the energy that underlies the universe, vaporizing the slabs.
Sentient beings throughout the galaxy mourned the loss of such a valuable artifact as a ringworld. But they also applauded the consummate artistry with which the craftworld AI accomplished the destruction.
*That* is the Culture.
It is canon that the only threat the Culture can't really cope with is something from a higher reality, passing through this reality on its way to somewhere... else.
That might describe the Tyranids, though, if their Warp paradigm applies to the encounter.
