How much did Lassic really know?

When Lashiec dies in PSIV, he clearly knows he is a servant of evil powers and expects to be revived in the future. Do you think he knew all of that back in PSI as well? There are a couple of conflicting backstories which suggest different things. In one he joins a religion in search of immortality - much like Zio. In another, he is slowly corrupted over time, sort of like the governor of Motavia.

So, did PSI Lashiec know he was serving Dark Force? Did he expect to be revived in his zombie form?

I think he would have known he would have be reincarnated considering he seemed very loyal to Dark Force in the first game. Lashiec also being some cult leader at the time he went all evil I'm also sure he was well aware he was serving Dark Force in PSI too.

I also think they touched up on this in Generations considering from what japanese I know theres quite a few statements about DF in his lines.