Nope, Raleigh doesn't show up at all. There's no time skip or anything, the plot moves right on and we don't even see much overt grief for Mako, her death just catapults Jake into his own story :) which uh :)

The scientists' plot was SO MUCH TRASH I don't even know where to start. Ugh. I get tired just trying to untangle it in my mind. "White boy gets himself possessed by demons from his own hubris and gets a bunch of people killed, but he's the innocent victim who needs to be protected" might sum it up.