-As the Federation, seize control over a Klingon shockwave ship or the Romulan ship that creates the rip in space. Once you get it, build a Nebulae class and research Gemini Effect. Use Gemini Effect on the captured super weapon and you then get two. You can identify them by seeing which super weapon has least amount of energy. Move quickly and use the copy of the super weapon. You can do significant damage to anyone, though the copy only lasts fifteen to thirty seconds. Use it as many times as desired.
-Capture an enemy construction vessel, then build up their tech. In some mods of the game, building a Romulan starbase will result in the Federation battle fleet a cloaking device automatically. However, once you build the yard the superweapon ships come from, you can build them as much (or little) as necessary.