What is the most powerful sowd in dragon quest 9 and how do you get it?

The most powerful sWord in Dragon Quest IX is the "Noble's SWord." To obtain it, you need to complete a quest that involves defeating a specific monster called the "Noble's SWord" itself, which can be found in the final dungeon of the game. Once defeated, you will receive the sWord as a reward. Additionally, it can also be obtained by completing the "SWord of the Noble" side quest, which requires some exploration and interaction with various NPCs in the game.