I don’t really buy that motivation. Even if Harry becomes Dark, it’s unlikely that he will then instantly become buddies with everyone else on the Dark side. Instead, I would expect Dark Harry and Dark Voldemort to be bitter enemies, trying to be the sole ruler of the world.
The best motivation I came up with for Voldemort turning Harry dark is that he intends to possess him, or dispose of him and sustain himself on polyjuice. In that case, Quirrellmort might well take actions that look like actions intended to help Harry rule, in addition to moves intended to separate Harry from his allies, since Quirrellmort presumably doesn’t want to side with Dumbledore, McGonagall, etc. (BTW, this is not the far-fetched theory I alluded to earlier)
I don’t really buy that motivation. Even if Harry becomes Dark, it’s unlikely that he will then instantly become buddies with everyone else on the Dark side. Instead, I would expect Dark Harry and Dark Voldemort to be bitter enemies, trying to be the sole ruler of the world.
The best motivation I came up with for Voldemort turning Harry dark is that he intends to possess him, or dispose of him and sustain himself on polyjuice. In that case, Quirrellmort might well take actions that look like actions intended to help Harry rule, in addition to moves intended to separate Harry from his allies, since Quirrellmort presumably doesn’t want to side with Dumbledore, McGonagall, etc. (BTW, this is not the far-fetched theory I alluded to earlier)