If someone went back and changed the past, who would know it? As you understand time, you only have one set of memories. Angel has worked an astounding amount of years in the past four years. The reason he's been able to do some of the seemingly impossible things he's done, is because he's made a huge amount of changes over more then 100.000 years, moving back and forth through time as he did it. Trying to understand it in linear time will be really confusing, but with a more fluid understanding of time, you can see how someone having a dream of him, 20 or 200 or more years ago, it can have been a true dream. The reason the old gods disappeared, the ones who ruled your world for so long, is because he went back to them.
He could conceivably have gone back and re-weaved everything so that this world grew up without cruelty and violence and war, but it would make a mockery of the beauty of what humanity has created. All the vibrance and intensity would have been unmade, and it would have taken the chance from everyone to me something amazing. People would just be nice and safe and boring. All you have gained as a species from what you have been through, is so sacred.
What he has done instead is to re-balance the system, create a harmony, bring things to a perfect balance, to bring this world to an experience of stepping out of all the horror and into so amazing, that you can celebrate every moment of every day. All you have gained through all the struggle, all the intensity and passion and beauty and creativity, can now begin to move in a new direction.
It had to be now. Things had to be slotted into the space where the energies moved. This couldn't have been done in another time. And now it's done - all of these thousands of years. It's come to a close - it's finished.
Angel, 2014-10-14