After killing Damien, losing contact with everyone, Aiden winds-up in Equestria, SOMEHOW, and finds that his hacking skills can reach new heights, from controlling minds, to read-out and manipulate abilities, and this world is loosing it's innocence, crime is rising, and Aiden will save it. Starting at the root.

Why? It's what she would have wanted.

I don't own Watch_Dogs or MLP: FiM, they belong to their respective owners, any references made referring to other media, that media belongs to the owners as well.