I've done it all, however

Getting said relic in 2.0 wasn't too bad, it was a decent challenge for the time.
Zenith was well just a tome cap.
Atma was a little bit of a pain, however nothing intensive, its not meant to be rushed in honesty, took me bout a week or two.
Animus took FOREVER, 1,500 myth for 1 BOOK then doing said book. thats 30 brayflox speed runs at the time.
Novus wasn't so bad, Hunts made it alot easier to manage, getting approx 15-20 Alexandrite a day.
Nexus was again, not too bad, just play how you normally would and boom it levels up.