There are two places in the map where i managed to get the avatar cube and survive. The first one was the screenshot below. Its in the back middle of the map.


You can recharge your double jump in the middle of the map where im standing, and theres a bridge for you to jump and chase the dragons tail, I only managed to get it once out of an hour of trying


This is where i found the most sucess with getting the avatar cube. Its the path to the left of spawn. We are not going to chase the dragon, We want to time when the cube is over the bridge and ground pound in to it. This eliminates the chance of getting the cube then dying because there's little to no land below us, and is also a fast restart since its closer to the start.



After about 6 or 7 tries i got lucky and managed to get the cube, Now comes the most stressfull part, Finish off the level. Take your time, watch where the dragon is and plan your route.



Best of luck to everyone trying to get this achievement, it is a frustrating one but fun.