Ok, wtf is going on here?
Aos is claiming that Syla and dad not only were but still are are working for Tanos...at least dad is since Syla is dead. Maybe dad just doesn't know the kind of person Tanos really is. He was going to kill the MC if he and the rest hadn't escaped. Dad is just a regular human so he might be largely unaware. But that's probably wishful thinking. If dad is in on Tanos' experiments he might need to die too.
I don't think MC dies, "dies". There is something that happens after he dies and is not the "end". It is for us we are playing the game. There is also the small dialogue after in the monster world where everyone is saying how they lost their "V" cards, and if you say that you lost it with Christie, Ella says:
Ella: Mmm, I bet. But honestly, I was hoping it was me.
MC: Too bad.
Ella: Ah well, next time.
MC: What does that even mean?
Ella: *shrug*
There is something here, or I'm just tripping.
Also, I think MC is way more important to Ella than is even portrayed