The biggest thing that Starkiller has ever taken down was a Star Destroyer, with [i]considerable[/i] effort. A Halo Ring is 10,000 times the size of a Star Destroyer, 30,000 times the size if we were talking about the original 12, and they can fire in any direction at any range, instantly, as the effect does not propagate through space and time, but rather ignores it and hits the target instantly. So you have to assume A) that SK is within range of the Halo B) that he will survive the automated defenses (which include Forerunner Warriors, each one capable of bringing down a city by himself) C) you have to assume he can do it at all, when the Halo can just shunt itself into a fractal dimension and be impervious to any and all damage (and besides, SK has [i[never[/i] shown the ability to bring down something the size of a planet) and then D) you have to assume he will do this 18 times to the total 18 Rings that have existed. In your fantasy, are the forerunners just sitting there doing nothing? Because that is literally the only way this would work, is if everyone in the SW universe suddenly stood still. And no, there is no creature in SW like the Flood and Gravemind, unless you can show me a creature from SW that A) is a psychic gestalt older than the universe, B) Can consume the knowledge of all it infects and improve upon alien technology, C) shut down all technology throughout 2/3rds of the galaxy, D) can create and control million-mile long indestructible strands of pure thought that can E) cut through solar systems like tissue paper and F) crush planets into black holes, can survive death to resurrect themselves at will, and G) expands a geometric rate of over 410 planets a day. As for your superweapons, again, small fry 1) The Star Forge is a glorified factory that can put out droids and ships at a pretty good rate; it is powered by the star it sits above. Forerunners can create a starship called a Planet Breaker, with no infrastructure, no factories, only a single design seed, and "grow" it within the span of a few minutes. some of the smallest fleets in the forerunner navy consisted of 70 Fortresses--100km long megaships--and 700,000 other smaller craft. They created the Onyx Shield world, a dyson sphere 2 AU in diameter (186million miles) which puts their production rates at somewhere around the equivalent of the second death star every 5 minutes. Star Forge is inconsequential to the Forerunners. 2) The sun crusher kills stars, something Forerunners can do with regular starships, and in fact was their standard mode of attack against the Flood. Simply trap it with slipspace interdiction and teleport it into another universe or throw it into a black hole. 3) The Eclipse would get a few kills in, and then be mobbed by the several hundred thousand other ships in the forerunner fleet. 4) World Devestators are basically crappier, slower and less efficient versions of the Star Forge, again, irrelevant. 5) Death Star II achieves what the Forerunners's civilians achieve; a Forerunner contracted Miner once shattered a planet out of [i]spite[/i] for his boss. Planets are considered resources to the Forerunners, and they blow them up regularly. 6) Galaxy gun is a smaller Death Star, easily trackable and destroyable 7) Centerpoint station can be traced and destroyed. All it achieves is something Forerunners always did (create and move stars; Precursors could create and move galaxies). This is my point. All SW has to offer are a select few superweapons that are outclassed by the Forerunner's regular technology. http://forums.spacebattles.com/threads/forerunner-feat-thread.236388/ All you need to know about the forerunners.