Krenim weapon ship

In several alternate timelines, the Krenim weapon ship was a warship of the Krenim Imperium.

It was capable of erasing civilizations from history, with the designs and construction headed by a military temporal scientist.

During the 2170s, the weapon ship was activated, and used against the primary enemy of the Krenim Imperium at the time. This temporal disruption restored the Krenim to their former glory, but also unexpectedly resulted in a plague that cost over fifty million Krenim lives. When the Krenim tried to fix the plague, they only caused more damage, via the ripple effect. (Fix one thing, cause another problem, and so on.) The lead scientist continued to alter history over the next two centuries, obsessed with fixing things. Along the way, many the civilizations were destroyed / wiped from existence.

The Krenim weapon ship was eventually erased from history when the USS Voyager banded together with a few local ships to fight back against the warship's meddling. Helped by inside actors on the Krenim ship, they were able to destroy the ship's temporal-based core. With the destruction of the Krenim weapon ship, the temporal shockwave restored the original timeline.

It is unknown what happened to the others on the Krenim ship, though they are presumed alive, due to the changing back of the timeline.