Pious Inquisitor
From Halopedia, the Halo wiki
Summary
Don't let its luxury fool you – the Pious Inquisitor is one of the fastest ships in the Covenant fleet. It is also one of the ships that attacked Earth in October of 2552 along with the rest of the Prophet of Regret's fleet.The Pious Inquisitor is also feared by the UNSC since the ship has participated on the conquering of many other planets and destroyed many human ships
It is also the location of the Halo 2 Multiplayer level Midship.