In Aaron's ears, he seemed to hear the 'Master of Corpse Concealment's' curse filled with pain and resentment.
Indeed, the ability of the 'Sword in the Stone' to destroy seems has its limits to heavily injuring or causing the fall of an ascended being.
This time the incarnation is killed, at most causing 'Master of Corpse Concealment' to be slightly injured, it doesn't really matter.
But without a doubt, Aaron has been deeply remembered and hated by this Si Sui.
Even, before his departure, he ruthlessly cursed him.
If it's an ordinary "Immortal", a curse of a Si Sui is enough to severely injure or even cause it to fall.
However, for Aaron, it's a matter of purification.
The 'Master of Corpse Concealment' probably knew that he couldn't do anything to the Green Forest Earl, who is protected by the 'Spirit of Illusion', hence didn't resort to more concealed pollution, because it's useless!
"It's just...this isn't the main battlefield."