Nerofest Farming

This link gives you the info you need.
https://grandorder.gamepress.gg/event-walkthrough-return-nero-fest-autumn-2018

Farm 10 AP for Bronze Medals, 20 AP for Silver, 40 AP Hero for Golden (it drops many silvers as well, also 15% chance of Hearts and 20% for Pages, best node ever) and 40 AP Conqueror (with 3 Chimeras, 2 avengers and 2 rulers) for many petals (note: all nodes drop a certain amount of petals, and the last one drop ONLY petals, a lot of them).

It will be the same once they change the enemies in the next stage of the event, and the drop rate of medals/petals is allways the same.