How did IG-88 almost Obliterate the Entire Star Wars Galaxy…
IG-88 was manufactured about 15 Years before the battle of Yavin on the laboratory world of Halowan, and not long after broke free from his programming and slaughtered his creators in a massive droid uprising.
After this, he and some other IG Units rushed to the industrial planet of Mechis III where he uploaded his own rebellious thoughts into the minds of every droid manufactured there, hoping to spark a huge droid revolution which would wipe biological beings from the galaxy and obliterate all life.
The next part of his plan took him to the second Death Star, where he managed to get his consciousness uploaded into it’s central computer, hoping to become the ultimate force in the galaxy and inspire millions more droids. The empire had no idea that he was in their death star computer systems, but Palpatine started to become suspicious after doors in his throne rooms kept opening and shutting.
IG-88 was actually the one who fired the superlaser at the Rebel fleet, letting the empire believe it was under their control and was moments away from unleashing his droid revolution signal, but unfortunately the battle station was destroyed by Lando Calrissian and the Rebels.