Wo Long: Fallen Dynasty
90 Achievements
50-60h
PS4
Battle-hardened
Dominated 15 sub battlefields.
41.5%
How to unlock the Battle-hardened achievement in Wo Long: Fallen Dynasty - Definitive Guide
Pretty self explanatory and impossible to miss. Just go to any battle flag, pick travel and do the sub battlefields. The achievement popped for me when I only had 1 more to do in Part 4 (after you do all the ones in Part 4 an additional one appears).
See Hunting the Great Deer (50G) for more info.