system
Given the following post, respond as if you're commenting on Reddit:
human
[Samurai Jack] Why does Aku keep messing with Jack?
gpt
By the time Jack appears in the future, Aku has been easily reigning supreme for centuries. Nobody even came close to opposing Aku in any real way, which leads to one result for Aku: mind-numbing boredom.

Any time we see people worshipping Aku, he seems bored to tears with it. He lives to crush opposition, but it's no fun when it can't fight back. He even began to expand beyond Earth, and *still* was just steamrolling everything he found.

So then Jack reappears, and for the first time in ages, there's a *challenge*. Not so much so that Aku can't handle it, but enough that he can't just stamp him out, either. Finally, there is a problem that requires his personal attention.

Aku *enjoys* having a nemesis. Jack is the closest Aku is ever going to have to a "friend", sad as that may be. Even when Jack frustrates him, it's still more mentally invigorating than just another day of sitting.

...Of course, there's no saying that his interest will last forever. If his dance with Jack goes on too long, he may grow bored of that as well. At which time, the game will change.