Alternate timeline(covers information from an alternate timeline)
The Nihydron were a spacefaring species in the Delta Quadrant native to a region of space near the Krenim Imperium.
In one possible timeline in 2374, three Nihydron warships joined the USS Voyager in its attack on the Krenim weapon ship. B'Elanna Torres and Harry Kim were assigned to work with the Nihydron to implement temporal shielding aboard their ships. (VOY: "Year of Hell, Part II")
The current state of the Nihydron Empire is unknown, after the temporal weapon ship was erased from time, undoing all the damage it had done.
- Star Trek Online's Delta Rising expansion reveals that in the restored timeline, the Nihydron were allied with the Krenim Imperium until the Krenim were defeated by the resurgent Vaadwaur.