After enough of Amon's forces had entered the planet, Artanis overloaded the core, destroying Shakuras. That said, the dialogue can become somewhat grating because the main Protoss leader Artanis seems to give heroic speech after heroic speech. The single-player follows Artanis as he seeks to unravel the prophecy of the Xel'naga. As you progress in the campaign, you will unlock new units and their versions.
Image Credit: Rowan Kaiser/GamesBeatAcross the 20 missions of the main campaign, it barely has a two-dimensional character to be found, let alone three.