yeah the speaker juked the shit out of ghaul lol. I still don't really understand what the traveler is either tbh. I've just accepted that it's a big ball that contains light and wants to do good. Traveler couldn't do anything as it was being drained of it's light and the Cabal ship was attached to it. Once Ghaul's spirit started begging the Traveler to notice him, you see the chains from that Cabal ship start to break and the light splurge building up before releasing. Could be that once you kill Ghaul in his physical form, he releases enough light that the Traveler is able to use it to implode.
the last few missions were dope af. some of the best stuff bungie has done imo. I got major Halo vibes from the majority of the campaign too, which isn't a bad thing.
