Get yourself some mega equipment and food for fighting dragons. In northwest of Karamja lodestone, pay 875gb to get in Brimhaven Dungeon. Go straight to Iron and steel dragon room in dungeon south, and kill 3 iron dragons to protect Hannibus while he is getting information from a Steel dragon. The Steel dragon’s information indicates there is clue on the wall next to Mysterious entrance, which translated in primer as ‘Dragonkin dungeon’ (means Queen Black Dragon).
Now travel to Grotworm lair in west of Port Sarim, go to Queen Black Dragon’s chamber in the bottom. Hannibus will talk with her via dreams, she will tell you her children are imprisoned in a dungeon on Gragontooth Island. Refill your supply and get a Ghostspeak amulet and ranged weapons. Ghost captain in Port Phasmatys will take you to the island, entrance at south. In the dungeon, fight the new kind of dragon ‘Celestial dragons’. Keep one celestial dragon alive as long as possible to let Hannibus understand it. Attack, let it heal fully, attack again, until Hannibus’ progress bar reaches 100%. If successful, the dragon will tell you something about a white dragon and tells you to seek King Black Dragon for more information.
Find the Artefact in Wilderness ditch northwest of loadestone. Head to Edgeville and use the Artfact to get in the King’s lair. Hannibus will get from the King that the white Dragon is the Therragorn, the last one of her kind. The king then will send you to her secret residence deep in the Wilderness. Only bring equipment and food that you are not afraid to lose, this is Wilderness you are exploring.
Once inside the mysterious entrance, Hannibus will converse with Therragorn, while three dragon-hunters will try stopping you and killing the Therragorn. Kill them to protect Therragon, and then she will take you away to safety, but passing Daemonheim she will be shot down by a fireball and fall. You will be waking in Daemonheim. Another Dragonkin Kerapac will inform you that Therragorn maybe dead and Hannibus is severely hurt. To get Kerapac’s help, you have to help Kerapac to save another Dragonkin Strisath, once a philosopher but driven mad by stone of Jas’s power. You need to harvest 25 Dragonkin memories from Protoplasmic wisps that from a portal Kerapac opens, then put them in Stisath’s cage. After that Kerapac will offer to send you into construct.
The construct is in fact the Shrine of Guthix, there you will confront Echo of Jas (level 190). Saradomin will heal the Echo, Zamorak attacks you with a bleeding effect attack and Lucien throws a powerful energy ball at you. Don’t worry they have only 1 point life each, not so hard to kill actually.
When battle is over, you will find Hannibus and Therragorn are both ok. Therragorn additionally bring back Hannibus’ great-grandson, Sharrigan. Now you have two options, persuade Hannibus to return his home with Sharrigan, or stay in Gielinor and let Kerapac find a cure for his people.
Quest formally complete here!