Y'know, I'll just quote it:
RUNE: Even though the battle against the ultimate fiend is over, my mission as Lutz must continue... You see, I must watch over all Algo. I'm still lacking in training and experience. I must continue to improve myself, and eventually pass it on to the next Lutz...
So... Is there the possibility that there's something else out there, since Lutz is needed to keep his watchful eye on Algo? Or is there some other reason why Lutz is needed?
Personally, I don't doubt there there could be other evils. I mean, the Earthlings came to Algo after PSI, (we see 'em in PSII) and they're from another galaxy. Who's to say that there isn't something else out there that could prove to be a threat?