The Dominion have torpedoes that go through Federation shields.
We live to serve the founders
The Dominion attempted to take over the Alpha Quadrant, sending its fleet through the Bajoran Wormhole from the Gamma Quadrant.
However their plan failed as the Federation and its allies soon beat the Dominion and Cardassians.
Notes: The Jem’Hadar attack ship is a small agile fighter, manned by a crew of a dozen Jem’Hadar soldiers and a Vorta commander, normally found operating in small hunter packs. Like all Dominion warships, the main weapons of the attack ship are phased polaron beams. When the Federation first encountered the Dominion, these beams were able to penetrate the shielding of Starfleet ships leaving them defenseless. The initial engagement with three attack ship resulted in the loss of the U.S.S. Odyssey, a Galaxy class starship, with all hands on board. Before the start of the Dominion War, Starfleet was able to salvage a crashed attack ship which allowed defenses to be developed against Dominion weaponry. Following their unquestioning loyalty to the Founders, Dominion attack ships will not withdraw from combat and have also shown the obedience to use their ship as a weapon by ramming large slow enemy cruisers.
Notes: The Jem’Hadar battleship was an experimental prototype warship built in the Alpha quadrant for the Dominion conquest. The battleship is twice the size of Galaxy class starship with more powerful weapons then any Starfleet, Klingon, or Romulan starship. The U.S.S. Valiant was destroyed by the prototype on an ill-conceived attack, as a result little is known about the true capabilities of the battleship.
Notes: Little is known about the Breen cruiser. Before the war what little information Starfleet had, reported that the Breen used organic technology in their ships. After the Breen joined the Dominion, Starfleet quickly discovered that the Breen possessed energy draining weapons that leave vessels dead in space. No defense was available until a Jem’Hadar attack ship was stolen which was being outfitted with the Breen energy weapon. Though possessing a terrifying weapon the Breen cruiser’s defenses are not any stronger then the average Dominion ship, easily destroyed by quantum torpedoes.