The Andromeda Galaxy spanned 220,000 light-years. Even the fastest Level Six artillery shells would take 1,032 years to cross it.
Of course, The Great Voyage Organization's Super Planet Destroyer Cannon shells equipped with Warp Engines could not actually travel that far. Even fully fueled warships could only manage roughly 100,000 light-years in a single voyage.
Even with the Feather Civilization's Warp Engine technology, The Great Voyage Organization's Super Planet Destroyer Cannon shells could travel at most 100,000 light-years.
However, the Super Planet Destroyer Cannon's conventional relative velocity was not restricted by the Warp Engine. Once the Warp Engine stopped operating, it could continue toward its target star at a conventional speed approaching the speed of light, though this process was far slower than the warp phase.
Therefore, The Great Voyage Organization had to launch attacks on the Andromeda Galaxy from every direction around it. Even so, it remained difficult to quickly reach the cluster of stars at the Andromeda Galaxy's core.
But that was enough, because there were enough shells.
And so, several years passed.
Many Super Planet Destroyer Cannon shells had already entered the Andromeda Galaxy. Yet because the Heavenly Maiden Civilization had focused on the wrong things, they failed to notice these shells producing faint warp traces.
More than a decade passed. More and more shells entered the Andromeda Galaxy, eventually reaching several hundred million. Perhaps because there were simply too many, the Heavenly Maiden Civilization finally noticed something unusual.
Through the information fed back by the Heavenly Maiden's Eye, they detected many warp traces. But perhaps those traces were too faint, so the Heavenly Maiden Civilization assumed they had been caused by low-level civilizations traveling through space and did not pay them much attention.
They even believed that The Great Voyage Organization had already left, perhaps for