Where ever they are located; Aaron and Jacob were once the best work buddies you could ever hope to find; they went as far as to travel across dimensions! But that seems too far fetched, correct? their machine worked but it malfunctioned yada yada yada...
They were secluded to very familiar yet very different dimensions...
Equestria; Twilight has received a new summoning book (screw originality) from the Princess, this book governs the summoning of demonic creations known as 'humans' the most chaotic ugly fiendish brutes from the other side of life. Twilight bucks up the first spell and summons two creatures instead of one.
Mayhem Ensued.
Elderscrolls, Fallout and MLP:FiM all belong to their respective owners.
Aha a good explanation