Plot branch : The zerg's air support is destroyed (B canon)
In order to take out the Zerg Swarm's ability to deploy flying units on their final approach, General Horace Warfield suggested to Jim Raynor that they destroy the platform. Due to the nature of the platform, surface detonations could not destroy it, so teams had to be sent to destroy the platform's coolant towers. Raynor and his forces moved on the platform, destroying the towers and causing sections of Char Aleph to melt down, destroying the nests burrowed inside. The attack succeeded, despite the arrival of a zerg battle group centered around a leviathan, and the platform was destroyed.
Plot branch : Raynor's Raiders destroy the nydus network. (A canon)
From Char Aleph, Kerrigan sent flying broods, including a leviathan toward the Terran Dominion battlegroup defending the Keystone.
↑Zeratul: "Kerrigan, this is Zeratul. I demand to know why you've taken our Matriarch." Sarah Kerrigan: "Actually, Zeratul, she's not the one I'm truly interested in. I stole her to get to you. You see, I need you and your brethren to kill the Overmind for me. The only way I had of assuring your cooperation was to take away that which you value most. However, I give you my word that once you've killed the Overmind, I'll allow her to return to you." Zeratul: "As if your word held any value..." Raszagal: "Zeratul, my faithful servant. You must aid Kerrigan in this endeavor. The Overmind is our common enemy. It must be destroyed to insure that our people will survive!" Zeratul: "You ask me to aid this vile creature?" Raszagal: "I do not ask this for myself. Nor do I ask it on Kerrigan's behalf. I ask you to do this for our people, Zeratul. Obey me as you always have... Trust in my judgement." Zeratul: "Very well, Matriarch. The Overmind will die this day." StarCraft: Brood War. Vivendi Games. Mission: To Slay the Beast (in English). 1998.