Oryx survives by the tithe of light from the strata of Hive below him. We break that chain. We kill the Priest that gathers the Tithe. We kill the perfect shape of victory (Golgoroth). We kill his daughters and leave him with only the Light he already has to eat. That light has been gathered by Ogres who are sent against us. We kill them, and leave Oryx unable to satisfy his hunger. Oryx attempts to use his worm to warp reality by using Doxology (A hymn of praise) to worship the worm - but we disrupt that death song. Oryx summons the bombs in order to kill us himself but we escape by running away. Oryx uses his Taken power to call a Shade to kill us, but we defeat the shade. The more power that Oryx uses to feed, the more power his worm demands. All we do is keep on disrupting that feeding - by freeing the light he wants to eat. It's not US that kill Oryx, it's his WORM that consumes him from the inside when he fails to keep up his deal to satisfy the hunger of the worm. EDIT: In response to the OP's edit - Oryx is trying not to kill us personally. We are seriously powerful, as proven by defeating his Warpriest, his children & his perfect shape. Killing us with his worm powers would require a massive feed for his worm. We may be a prize big enough to provide that feed, but he is greedy and confident. If he can set up his Taken to kill us (non worm powered as he TOOK that power) then he can take a bigger personal chunk of our light and only tithe a tiny amount to his worm. The more of his worm power he uses to kill us, the less our deaths will satisfy his worm. It's good old fashioned greed that makes him vulnerable. EDIT 2: In response to the OP's edit - Read verse 4.9 of the Books of Sorrow; Quria, Blade Transform deduced the sword logic and made it work, and it was a Vex. So clearly sword logic does apply to beings other than the Hive and is not intrinsically linked with feeding a symbiotic worm. If that is true, then it follows that by right of slaughter WE have established ourselves as a power in the throne world.

Well yeah. Been destroying entire worlds for billions of years? Shut down by six jackasses doing The Carlton.

We killed everything that made Oryx so strong, he was weakened to the point of Crota's strength. If Oryx had time to heal, then yes it would be impossible to kill. Think of something more realistic, like a bear. With 0 damage a bear is very hard to kill, almost impossible by a group of 6 people, but if you weaken it through traps and things like that even a single person could kill it.

That was exactly the same thing I said. There is no way to kill the Oryx that is portrayed in the books of sorrow,at least by guardians. I really don't buy it. In fact,it's just too unrealistic and absurd,even by destiny standards.

What is the worm

We did defeat the heart of the black garden, and hive prince, both of which were gods. So, we have that going for us.

My biggest question with the raid is that if we guardians are beings of light then why does the light kill us when we detonate the orbs? Shouldnt the light not harm us. Perhaps we are beings of darkness

Well, I'm gonna go off of other people speculation here, no facts just let's say they were. So let's say a good amount of the player base is right, and the worms are actually ahmkara. That they gave the three siblings the power they have. Okay well the warlocks already hunted down the ahmkara and basically wiped them out, so wouldn't be too far a stretch. Now let's say those speculations aren't true. The hive fought a specific race, called the ecumenes (or something like that) and almost lost themselves. The traveler was not once mentioned in this battle. So we dont know id they really had the Light in their side to help fight Oryx and his sisters. We also know that the hive have defeated the traveler numerous times before, but the traveler would always retreat. But what about now? The traveler stayed to protect us. Or, maybe did it use us, knowing we could save it from eternal pursuit? So, in conclusion, we have this. The traveler stayed with us where he retreated for others. We don't know if he gifted other races the Light. The hive almost got defeated by a race when all three of the royal siblings were there. We only faced one. Yes the dreadnaught blocked some of the light, yet we were still able to wield it. So while I agree with what you say and have been saying it since the raid dropped, I can see where they left some holes where we might have been able to defeat him where others havent.