Gestalt X (This creature gets +X/+X for each other creature that shares at least one creature type with it): This represents the hive mind of some organisms. It's simpler than the interactions between Slivers or Allies, but it keyworded nicely.

Modal spells and Entwine X (Choose all modes if you pay the entwine cost): These represent the ability to travel through time and potentially change events. Not all timelines are mutable, however.

Exile: represents the movement of spells through time and space.

Artifact creatures: channel the science fiction feel of Doctor Who. This includes colored artifact creatures, showing the blend between flesh and metal.