Construction beginning/end
Sonata became more than a battlefield. It became a mythic symbol. Entire generations were raised in its steel corridors and subterranean habitats. Hardened by scavenged UEG and UNSC tech, its defense grid became a prototype for the Citadel Bastion doctrine, defining UCG architecture.
During this time, the Dawn's Wardens were first conceptualized, initially as youth self-defense units, then codified into a full-scale militarized academy system to ensure that every child could kill if they had to.