Ship: The Lightmare Relies on the ships artillery laser to take down enemy shields, then shoots it with the Hazard Beam to destroy the systems & crew.
Ship: The Dream This ship uses its beam weapon to annihilate ships, and if that doesn't take them out than the railgun will.
Ship: The Nightmare Has no shields, but the ships cloaking and hacking will keep it alive long enough for the super-weapon to charge, the Nightmare Beam melts through everything it touches.
Incredibly overpower but one of the most enjoyable ships i've flown, had a lot of fun with all 3 types. A small warning for anyone playing with Captains Edition, Type A and type C have a bug, if your artillery shoots at a ship with only 3 or 4 rooms it will crash the game. Often the AI ships in nebulas have less than 5 rooms. I have no idea about modding but I'm guessing the artillery needs at least 5 rooms to shoot at and when it can't it just hangs the game. Simplest solution is to just unpower your artillery when facing one of these enemies.