The Terran Incursion, or Earth's Invasion, was a period of extraterrestrial warfare between humanity and the Anathema lasting through the Incursion Era of history. The war was ended by the rise of Kisaris Amaranth and five other sorcerers whose powers turned the tide of battle versus the alien creatures.
Beginning in 2011, the Anathema, an extraterrestrial race began landing on Earth, and not soon afterwards, set their sights on exterminating its current inhabitants. With telepathic communication and supernatural abilities, mankind's technology could hardly stand against the lesser Anatheman grunts. Whenever anything of higher power stormed on to the battlefields, the opposing armies were forced to retreat if they weren't eliminated outright. The Incursion continued in this manner across the world as more Anathema were reported landing from space almost every day. While man's armies weren't outnumbered by them, their powers were unmatchable by modern technology and almost every battle in the war was a loss for humanity. By early 2012, mankind had already begun retreating to an underground existence, with most of the population relocated in subterranean shelters and tunnel networks by the end of the year. While there was nothing stopping the Anathema from ruling the surface world, it was much harder for them to hunt humanity in the underground as any single invading force could be immediately focused down by either defenses or crushed by a voluntary collapse of the ceiling above them. Without means for either side to reliably stage an assault against each other, the Incursion was at a stalemate.
Nearly a generation later, magical powers started to be found in humans, with Eldruin Falcon being the first seen in the public's eyes later followed by others like Hikaru, Talaya and Trista. Kisaris Amaranth would be tasked with uniting these sorcerers under a common force in a new offensive against the Anathema. With their own powers strong enough to fight against the higher-powered Anatheman overseers. For the first time in decades forward-operating bases were established on the surface again, including FOB Lodestar and FOB Catalyst.
With the rise of the sorcerers also came the rise of the Inquisition, a (not necessarily religious) force that believed that magic was either inherently evil and deceptive or that the sorcerers lead by Kisaris were Anatheman spawns disguised as humans. As humans they fought against the Anathema as well, but primarily targeted sorcerers and anything associated with them so they wouldn't be "destroyed from the inside-out".
The sorcerers defeat of the Anatheman Matriarch and crippling of the Inquisition forces marked the end of the Incursion and humanity would soon return to the surface, beginning a new era in human history known as The New Frontier.