As far as I'm concerned i think time travel here is similar somewhat to how time works in mcu, if you time travel to the past and create a huge change there it won't affect your future but creates a branch timeline instead
To put it in simpler terms
I think the guy who transported the ceo was the demon where (i think) the ceo died in his timeline and now he went to send the ceo to the past but this time to create a branch timeline where the future is not the same unfortunate as him
To understand how mcu time works if you travel back through the past and kill a friend in there if you go back to your future your friend would still be alive, i.e it means you made a branch timeline where your friend died so there would be two future timelines the one where you came from and the new timeline you created where your friend is dead
But thats if this time rules applies to this story and i think the demon in where he was transported remembers the ceo
So, this demon doesn't remember ceo (slave)? But why he (in another form, time, world) brought him back to those times, dimension? What benefits will he gain if he doesn't remember anything, why does he want to change history if currently he lives in another dimension/time.
I know this is a common isekai storyline, but it always puzzled me.