A Delta Quadrant species who join the coalition Janeway assembles against the Krenim weapon ship in the second part of Year of Hell.
The Mawasi appear in the Voyager two-part story Year of Hell. They are a spacefaring people living near Krenim territory.
In the altered timeline of 2374, after months of running fights have left Voyager a wreck with a skeleton crew, Janeway takes shelter in a nebula and then seeks friends. The Mawasi and the Nihydron both agree to help.
A small fleet of their ships, fitted with Voyager's temporal shielding, goes with her in the final assault on Annorax's weapon ship. The allied ships suffer badly in the battle. When Janeway rams the Krenim vessel the whole timeline resets, and the alliance, like the year itself, never takes place.