Humanity as a whole is known as many things to many different species. Yes, while they are terrifying deathworlders more than capable of destroying everyone and everything, they’ve always been willing to lend a helping hand to all those who ask, and even those who don’t. So was it really that big a surprise when, after a powerful warmongering race declared war on humanity that half the universe flocked to humanity’s aid? -- Anon Guest
For every bully, there is a bigger and meaner one. Some may even have a higher intelligence. More often than not, they just fight dirtier. This one called themselves the Mighty Catrapy of Zorjesh, and were apparently offended by anything not Zorjeshi in general and humans in particular.
Humans had a knack for being everywhere and, what with Sol's abundance of one-way wormholes, there before anyone else could lay claim to the territory. The Zorjeshi had a similar definition of 'paradise' to Humans and, as more-or-less equals on the Deathworlder ratings, decided they could probably beat them in a fair fight.
Except there was one little thing that Humans did that the Zorjeshi did not.