Shining Armor dreamt about him fighting this large creature as he tried to save Equesrule from the hands of a beast like creature known as Sombron. The creature had captured all the sages including Princess Cadance. He saw himself fighting hundreds of monsters getting stronger each time until he save them all
...This is not a prologue.
This is a small paragraph telling us about the dreams of an AU Shining Armor that are written with very bad grammar.