The reason why Lin Jie spent so much effort to enter the Hero-Level was to first obtain the reward of "Whole Team's Skill Point +1" for the first clear of all Hero-Levels, and secondly was the special items dropped in the Hero-Level.
The stronger the monster, the higher the drop-rate, which was the common rule in The New Age.
Such as killing Sea Mage Laney in his complete state, not only would the complete "Sea Condensing Spell", which Lin Jie had learned, would be dropped, one would even be able to obtain the various special items of the Poseidon Shrine, which included the fragments of Sub-Legendary equipment, mission clues, and so on. Meanwhile, the reward for killing the weakened state of Sea Mage Laney would be tens of times worse than killing him in his complete state.