Nebula-class light battleship (EXverse)

The Nebula-class light battleship is a heavily-armed class of light battleships built specifically to fight the heaviest Covenant warship. Being the first battleship in UNSC's history, it was slow despite being designed to be a "fast battleship", but it was also extremely powerful, to the point that it was feared by many alien shipmasters.
At the time of the Covenant invasion the UNSC found itself underpowered against an overwhelming opponent. Nebulas were one of the answer to that issue, as they were capable of tearing down a Covenant cruiser with ease, at the price of being immobile; indeed they were armed with one of the most powerful MAC gun of the time, which however required a massive amount of energy. Despite being criticized because it was substantially armed with the same MAC found aboard , the class was produced in two separated blocks, because in the end it proved to be highly successful in its primary role, namely the ship-killer role; however, the loss of the colony of Camber in 2546 led to a serious resources' shortage, which forced Naval Command to interrupt Block II's production, as it shifted its efforts both towards the experiment of streamlined manufacturing techniques - which required new designs - and the completion of Project: OUROBOROS.