system
Given the following post, respond as if you're commenting on Reddit:
human
[Samurai Jack] Why did none of the aliens Jack helped come back to liberate earth from Aku?

In the old videologs and records of the time, it is clear that Jack helped at least one powerful alien species (the wasp people), and possibly several others with advanced technology. Why did none of them return to earth to liberate us from Aku?
gpt
Because their conventional weapons don't really work against Aku. For example, when Jack visits Atlantis and those creatures try to fight back against Aku, their weapons are basically powerless; their arrows go straight through him. Only Jack's magic sword works.