Weapons of mass destruction that have historically been used in the Pocket Universe include nuclear and anti-matter bombs, asteroids and nucleuses of comets directed against planetary surfaces, and biological and chemical weapons. This was particularly true by the New Shi'ar Imperium and to a lesser extent by it's armed foes during the Era of Anti-Imperial Rebellions. A number of worlds were mostly devastated by such weapons.
In recent centuries and millennia, the use of weapons of mass destruction have become extremely rare. Even the Cylons, who might overwise use weapons of mass destruction against Humans, are reluctant to do so because they might injure or kill innocent non-humans.