My theory is that sayaka is good(?) and she wants to get rid of the damn AI and needs kurumi as she is the last person alive without the regis(?). I also think sayaka is the one who blew up the familie as she came to know their plans(?) for future? remember sayaka is the only one who is well rooted into the familia's tops. and she is drugging kurumi cuz if kurumi gets the hint she will defo go back to where hikaru is(?)