[Suicide Junkie]

If you have an alliance, it is already quite powerful.

You should realize that no mod can make it "impossible to win" without an alliance.
You can always take on somebody your own size, or smaller.

Even in stock, though, alliances are significantly stronger than the sum of their parts.


Perhaps you mean a mod which makes it easier for allied players to attack and defend together?

Carrier Battles mod has relatively slow damage in combat, which means that as long as both players' forces are in the sector at the same time, they should fight very effectively together.