One year, and almost 2 months this war has been waged, continually expanding, bringing in more and more into the fight. Not ones to be discouraged, the villains of the universe see it as more to gain; another universe joined the war? Good! More foot-room.
Begin semi-useless back-history:
Stiff resistance left and right, but the combined forces of the Dominion, Drahk, and Empire had extended their reach very far, nearly half of the Star Trek galaxy and over a third of the Babylon 5 galaxy had fallen.
It took a while for the Empire to get adjusted to fighting alternate realities with different laws of physics, initially shooting themselves in the foot more than the enemy. In all actuality it never was doing poorly, fighting other nations in a full-scale war and fighting off a massive rebellion at home. The Emperor is fairly greedy, and the chance to triple the Empire's size isn't one he's about to pass up.
The Drahk had realized what a powerful ally the Empire would be and tried to ally themselves as soon as possible. There was a…misunderstanding but eventually it was worked out. Without a real homeworld the Drahk are the only evil force without firmly entrenched, defined territory. The Shadow technology they had access to was their main contribution. Originally simply wanting revenge, they now see the chance to create an empire of their own.
The Dominion is the source of most offensives in the Star Trek galaxy, using B5 and SW travel methods they've conquered even more than the Delta Quadrant and their holdings in the Alpha Quadrant. Able to mass-produce ships and soldiers it's military power is surpassed only by the Borg in the ST galaxy. The Founders are perhaps the most ambitious evil force of all, wanting control of all "solids."
End semi-useless back-history:

We come into what is basically evil central now that Coruscant is toastified. It's a massive complex deep inside Imperial space. Outside Imperial Star Destroyers are seen under construction along with Imperial, Dominion and Drahk patrol ships. Inside is a huge tactical room in which representatives from the three Empires plot the destruction of the good guys. Darth Vader is off in the corner slurping down a chocolate shake while everyone else does the thinking.

Vader: hmm…out. Must get more chocolate…

Weyoun: *stands in his way* Don't you think you've had enough of that crud?

Vader: You dissin' sugar?

Weyoun: Considering that you've been eating that stuff for a few hours straight, I'm wondering about your sanity.

Vader: GRR!! *force chokes him and kicks the corpse down the garbage shoot* Stupid loser…

Changling: *sighs* Time to make another one…

Emperor: You never get in the way of Vader and chocolate…I have the scars to prove it!

Vader: *stuffing his face* Sorry m'lord, but you did try to put me on a diet.

Drahk: Anyway, on to our battle strategy. I think maybe we can fix this whole war-of-attrition attitude you've had and take more space with less casualties.

Admiral: We don't really care about casualties.

Thrawn: Speak for yourself!

Admiral: I more-or-less was!

Drahk: Enough! Do we really need to argue with each other?

Thrawn: With babies like him I really shouldn't waste my time!

Admiral: WHY YOU!

Emperor: DOWN! No one attacks Thrawn, he's our best admiral!

Admiral: *pouts*

Drahk: so…about making a new strategy?

Emperor: It's working well so far, and we have a lot more to lose than our enemies. I don't see any point in changing.

Drahk: All right, how are our campaigns in universes outside of the main three doing?

Changling: From what I've been told, well for the most part. Large patches of space and resource-rich planets we've conquered in universes we have partial access to have fallen under our control and should keep us fighting far longer than any who'd try to stand in our way.

Vader: There have been a few flops though. I hear the forces that found the Dinobot's homeworld got thrashed.

Thrawn: It's a planet-sized factory, but it's not something we can take over, at least, not with out abandoning multiple offensives. Not all worlds with huge robots are unbeatable though, in one universe a Star Destroyer obliterated multiple robots called "zords" with ease and took over their versions of Earth.

Vader: *puts mask back on to hide messy eating habits* Let's dial up and check on some others.

On "The Planet of the Apes":

A large amount of Storm Troopers with dented armor run by.

Storm Trooper: THOSE MONKEYS MEAN BUSINESS! RUN!!

Last of the Storm Troopers run by closely followed by a army of primates.

Changling: You really ought to consider upgrading your soldiers…

Vader: Shut up, you're Jem'Hedar aren't doing much better…

In Anime World: More specifically, Sailor Moon.

Sailor Moon: In the name of the moon I will punish you!

BLAM!! KICK! POW! WHAM!

Changling: I'll concede…that is humiliating…

Drahk: In that universe no attack works unless proceeded by a high pitched battle cry that in some way describes the attack. I guess they didn't want to demean themselves that way…

In a vaguely familiar place…

Storm Trooper: RUN!!!

Storm Trooper2: I hate this place! There's HUGE monsters everywhere you look!

ROOOAAAR!!

Storm Trooper3: YAY!! It's Godzilla! I thought he'd left us!

Storm Trooper2: Uh….he doesn't look very happy…

Vader: ….ewww…

Mail guy: Um…I have a package here, addressed to the Emperor…

Emperor: It's from the Breen homeworld…

Changling: The Breen?

Emperor: Yes, I sent a battle fleet to take over there homeworld. This must be confirmation.

The Emperor opens the small box and assorted bits of ISD and TIE hull fall out, clanging on the floor. Also inside is a card, it reads on the outside "Dear idiots," and on the inside, "Never try that again. Menacingly, the Breen."

Emperor: …well.

Vader: *grabs the card and flips it over* Hallmark…geez, they do have a card for everything!

Drahk: I vote we take the Breen's advice on this one.

Changling: OI…must you people attack everyone? The Dominion had just started negotiations with the Breen!

All the Imperials look at each other nervously then try to discreetly look away.

Vader: So…how's that development with the Junkions coming?

Admiral: Not good. They're very tough, and they've been found in Imperial space!!

Emperor: What? Where?

Admiral: Just some minor outer planets…here, take a look.

A Star Destroyer is seen tangling with a Junkion ship. The Junkion ship isn't suffering much damage but has rammed some good dents into the SD to compliment the weapons fire burns.

Wreck Gar: High-did-le-o neighbor-inos! How's things going on your side of the fence?

Captain: Um…anyone understand that?

Lieutenant: Uh…I think so sir. Just a question of how we're doing…

Captain: Not very well thank you, now LEAVE We've still got 8,000 battle ready Storm Troopers on this ship!

Wreck Gar: We'll see that, and raise you 400 Junkions.

Captain: Uh…You win…

Later, Planet-side.

Junkion: That's the last of 'em pardner.

The Junkions are seen to have dispatched a large amount of Storm Troopers and stomped a ground base flat.

Wreck Gar: Friends, city men, oppressed dudes, lend me your ears! This is a special once-in-a-lifetime offer! Act now to destroy Vader, kill the Emperor, and eliminate even the toughest stains!

Junkions: Destroy Vader! Kill the Emperor! Eliminate even the toughest stains!

The large crowd of Imperial citizens get in a huddle and start talking with each other, soon they decide that it's a catchy tune and they have nothing better to do.

Crowd: DESTROY VADER! KILL THE EMPEROR! ELIMINATE EVEN THE TOUGHEST STAINS!

The Junkions and their newly found rebellion sympathizers head off in their ship.

Vader: Not good.

Admiral: …I have to agree with you on that one.

Emperor: Got any good news?

Admiral: Klingons rampaging in our space with rebel help…Minbari rampaging in our space…rebellion growing bigger…our best hackers killed by a sentient super computer…a total of 26 Star Destroyers and 32 lighter craft deserted…some sort of "Mayhem Project" the Federation is working on… Um…the Federation's new shipyards have been destroyed. Some members in the Romulan Star Empire have been trying to either switch sides or drop out of the war…and we may be able to retake an offensive role soon if we play our cards right.

Vader: Thrawn, have you sent out the second battle fleet to Minbari space yet?

Thrawn: I tried, but they wouldn't go and said they'd rather be force-choked. I told you that attacking the Minbari directly like that was a mistake.

Vader: Rule one of living in an evil empire, NEVER disagree with the boss!!

Thrawn: Too true.

Emperor: Stop arguing!! Now, I have some ideas. I think we should stop looking for other dimensions, take it one step at a time so to speak, for now we'll focus on the two main galaxies.

Drahk, Changling, Admiral, Thrawn and Vader: WE TOLD YOU!