Not so long ago, in a galaxy not too far away, there were two civilizations at war. Both were at war because the leaders of both wanted more and more power. Both were advanced and mined the stars. Both had an extensive fleet of powerful ships — everything from fighters to transport ships, to destroyers, to planet annihilators. Each ship obviously had it's strengths and weaknesses. The fighters were fast, maneuverable, and could hold relatively powerful weapons, but had very little protection for the pilot. The transport ships resembled modern day aircraft carriers. They were large, slow, heavily armored, and not very powerful on their own, but could hold many fighters within. The destroyers were smaller than capital ships, and much larger than a fighter. They were slow, have a lot of armor, and a lot of ship-to ship firepower, but would be easily defeated if sent against planet based defenses. The capital-sized planet annihilators held insanely powerful burst weapons. These ships were extremely slow, and sitting ducks in ship to ship combat if unguarded by fighters or destroyers. A well piloted fighter could potentially destroy one if it shot at the right spots. However — put a large, slow target in front of a planet annihilator, charge the weapon, and say buh-bye. It could shoot through a few destroyers, penetrate the transport ships behind them, and still do significant damage to planet based defenses that the other ships were guarding.
(Much Shorter Version):
Two vast civilizations at war, big ships, powerful battles. Lying politicians striving for more power urge the war on. All ships have weaknesses — nothing is safe from all attacks.
A lone soldier in one of the armies, (call him Bob,) becomes fed up with the lying politicians' struggle for power. He takes his fighter, disables the tracking system, and flies off during the night. (night in space, really? -yah.) A few months into his journey, he sees another ship in the distance. Its appearance is of nothing he has ever seen. A message suddenly appears on his highly encrypted top secret communication device thingy, which should have been restricted to his army only. "Greeting hu-man. Why come you to realm?"
Bob considers trying to trick the strange beings, but thinks better when he considers that they were able to communicate with him on his highly encrypted communicator thingy, which means that they are beings with obviously far superior intelligence. He replies, "The leaders from where I come from only care for power. They have torn apart my once peaceful homeland. I was a soldier in their armies, and deserted out of sheer disgust."
The strange alien being replied, "In realm, there is peace. You be quite extraordinary to be escaped undetected from your fleet. For your hu-man race is quite dumb, but they do posses some smartness. We a civilization that strives to knowledge, to understand everything. You possess knowledge of the hu-mans. We will welcome you."
To skip through uninteresting parts of the story
Bob lives with the alien civilization, who turns out to be quite advanced. He shares with them everything he knows of the humans, and is educated himself of matters that the greatest scientists from his home would not have even guessed.
One day, the king alien, (who is a few hundred centuries old), says to Bob, "I see that during the years you have been in realm, your leaders not ceased meaningless squabble. For much as I know, I not comprehend why they would keep their meaningless fighting. I decide to end it for them. I not, and entire race not do it. We much more important things to discover — to understand. But you a hu-man. You understand them. You end meaningless war."
Bob had trouble comprehending this, but managed to say, "But… How? In every battle I was in before, the sides were very well matched. Even if I could convince all of one army to side with me — after deserting like I did, there is very little chance I could lead them to victory"
The alien king replied, "You need no help. You will win alone."
Bob still could not really understand this, so he asked, "and just how will I, alone, win? the fighter I came here in is probably outdated — I was a good pilot, but I am no where near good enough to win the entire war!"
The alien king replied, "I see to it — you be well prepared."
The alien king has the smartest members of his race build Bob a ship — A ship that the smartest scientists form his homeland could never have imagined.
The armor, being a composite form of X-Matter, Unobtanium, and Handwaveidium, is indestructible, incredibly lightweight, and extremely rigid, and can be quite thin. It can be set to reflect incoming energy weapons, and can shatter the hardest kinetic projectiles.
The engines, powered off of a Qutonium reactor and expelling dark energy, can propel his ship faster than anything else in existence. The engine can release its charged energy in a burst powerful enough for the ship to lurch forward at speeds sufficient to warp space and create new wormholes. Due to more Unobtanium and Handwaveidium, Bob somehow does not implode from the acceleration.
The power of the weaponry on Bob's shiny new ship is (as the alien kind described) "Tested - the energy broke many of best instruments and made testing chamber very melty. You will find it easy for Sustained fire - last a few thousand years before depleting reactor core."
Now for the question:
With Bob's invincible ship, would he be able to take over the galaxy? If not, would he even be able to successfully stop the war? And if he did stop the war, would he be able to make everyone peaceful again?