On-Topic: I can provide relevant quotes from some previous Forerunner threads. The first one I'd say is more important. They artificially accelerate the rate at which universes age and then use the void
| Fred stood on the brink of creation, watching universes wink into being, then swell into silvery eggs of brilliance and implode into nothing...He saw the birth of all things and the end of everything, saw the wave of eternity roll across a universe of universes and swallow them all in the blink of an eye. | | |
| | ~ Denning, Troy (2015-09-15). Last Light (HALO) | |
| As the reflective orb rotates beneath my ship, I see also the outstretched, feather-like plumes of vacuum energy pylons, drawing in the potential of an infinity of alternate realities ... aborting untold numbers of nascent universes to supply Requiem's power. Strange that these cosmic deaths have never before struck me as cruel and futile. All of Forerunner technology has been made possible by drawing down vacuum energy. My own life, all that I know, arises out of cosmic predation. | | |
| | ~ Silentium, Ch. 33 | |
Both can be found in this
thread. There's more, but I decided to quote those two as they dealt with the Forerunner fuel gathering from other universes.
Another, albeit off-topic (but still posting here, don't really want to make yet another Forerunner thread) thing, the Forerunner profile is rather lackluster in formatting compared to say, the Covenant. They're missing gender, age, classification, speed, durability, lifting and striking strength, stamina, and intelligence.
Age, Gender, and Classification are easy enough.
Intelligence could be added as:
Intelligence: Exceptional (Far more advanced than present day UNSC and Covenant, capable of engineering structures on an astronomical scale (and casual planetary manipulation), quantum-scale technology, creating (See: Huragok) and devolving life, mold light into a solid state for a vast variety of purposes, creating fully sentient AIs (Ancilla), and coordinate their forces against the Flood, which in truth, are deformed versions of the Precursors)
Forerunner armors also have reactive Eevolutionn to an extent. If they manage to survive a hit from an enemy attack, the armor will adapt to better resist that weapon. (Escalation, Part 10, it is stated that they can't give the Didact the chance to adapt his own armor to their weapons).
There's more powers and abilities for individual Forerunners in that respect thread, but this is about the Forerunners destroying universes to power their light-bulbs feat.