V-15 Dreadnought
The Dreadnought is an ultra-heavy Battleship, comparable to the Tavara and other giants. It's quite slow but his devastating armament is able to crush whole fleets. Newer versions of the Dreadnought are also equipped with a Hyperspace Disruptor which will deal double damage to stations. The Dreadnoughts special ability is Overwhelming Presence.
As the Dreadnought costs 6 credits it is a unique tool of war. It's best used within a small fleet to counter and destroy an enemies offense. Its special ability gives you immense control over your opponent, cause his or her vessels won't be able to do much but receiving massive damage. Two Dreadnoughts heading to a base should invoke a Wolf-359 like panic!

Overwhelming Presence
All hostiles within an area covered by 50 percent of the Dreadnoughts sensor range are incapacitated for 8 seconds. Incapacitated targets can neither receive nor execute orders.



And as some additional Dominion info, here comes the complete Mixed-Tech list:

Federation Technology:
- V-15 Dreadnought
+ 50 Defensive Value - C-17 Siege Cruiser
+ 3 Defensive Value
+ The EM-Blast special ability will shot down the engines of affected units in addition to the normal effect - B-5 Battle Cruiser
+ Double-Layer Shields (increased Defensive Value)

Klingon Technology:
- V-15 Dreadnought
+ 50 Offensive Value - A-20 Attack Destroyer
+ 1 Offensive Value
+ Superiority Destroyer passive ability - A-26 Bomber
+ 2 Offensive Value
+ Tetrion-Photon Torpedo replaced by Compound Tetrion-Photon Torpedo

Romulan Technology:
- V-15 Dreadnought
+ 50 System Value - C-11 Interception Destroyer
+ 3 System Value
+ Cascade Feedback replaced by Shield Recharge - T-15 Heavy Cruiser
+ 2 System Value
+ May be refitted

Borg Technology:
- V-15 Dreadnought
+ 20 to all Attributes - S-2 Escort Cruiser
+ 2 to all Attributes
+ Alpha Ketracel White replaced by Gamma Ketracel White which will last longer and will not cause crew casualties - T-15 Heavy Cruiser
+ 2 to all Attributes
+ Assault will fire over long range instead of short range