Still Crazy After All These Years
Maeve nodded. Her thrashing tail belied the interest in the topic. "Then I'm sure you were aware of how locked you were in this timeline. You weren't able to change the past so much as fulfill your role in it. To my knowledge, no magic or supernatural ability has been able to travel through time in any fashion other than forwards or backwards along a single trajectory. Simply put, one cannot move from one timeline to another. This creature, however, sees multiple timelines at a given moment, and anchors himself onto whichever outcome suits him best. He moves across the scale of probability the same way you or I walk across a room. What this means is: if you're seeing him, then whatever he's after, he's already gotten."
Maeve could see she was getting carried away with the topic, and caught herself. "The reason I'm telling you all this so you don't go trying to fight him. You can't. We've tried, and it was disastrous. Frankly, I'm not convinced he's truly corporeal. The worst you can do to him is thwart his plans, and the only indication you'll get that it worked is that you'll never see him again, because he's in the outcome where you failed. Be very careful how you deal with him."