In the game, there were many techniques for defeating bosses.
Though Liuli was written as an evil sect's Holy Maiden at late Nascent Soul stage, the secret realm's suppression reduced her to early Nascent Soul when she appeared. The protagonist only had peak Foundation Establishment at that time, two whole realms below her. Basic attacks couldn't even outpace her healing.
To break through Liuli's defenses required using terrain-based strategies.
This ancient palace that imprisoned the thousand-year tree spirit was similar to the Mountain Temple - the battlefield was filled with hidden traps. Poor execution meant instant death for players, but skilled positioning could lure Liuli to specific spots where triggering mechanisms would allow the terrain to deal heavy damage.