Let's start with the basics, shall we. Time lines altered, information that doesn't belong taken to and from one world, universe, time, to another. You have species and technology where they don't belong. Universes colliding with each other that were never meant to touch.

Imagine your world is surrounded by a perfect sphere of glass. Every time you drag something through time or space you put another hole in that sphere, creating cracks that spread and grow. Getting worse and worse until it shatters into a million tiny shards.