At this time, visit the lender and OSRS gold stock up for a struggle. Head to Oldak and inform him you're prepared. Sigmund and Johanus Ulsbrecht will teleport in, along with the HAM mage and HAM ranger, and some guards. Sigmund uses his 43 prayer, again, and Johanus can use range and melee, as well as prayer.
After 1 minute of fighting, several Lumbridge Guardsmen, led by Jimmy that the Chisel and Aggie (remember One Small Favour?) Will appear to arrest the HAM members, so you may just have to worry about Sigmund and Johanus then. Zanik will take Sigmund, whilst Johanus comes at you. You can either use an Historical Mace (it won't remove his prayer though), complete Veracs, or you might just switch styles every now and then.
When they are all dead, the HAM members will operate. No, they're not dead after all. Oh well. Zanik picks up where she left off. You point out that the box at Yubiusk slammed shut after you freed her. Zanik claims that because it has some energy of Dalgroth, it is near indestructable. Zanik cites that while trapped, she heard things about Bandos, including that Dalgroth is his supernatural ability, making a number of his ogre followers around immortal.
You propose destroying the box the exact same way you conquered the Ogre Shamans in Watchtower: using a potion. Head to Yanille and also make a potion exactly like the one from Watchtower, in other words, with guam foliage, jangerberries and bat bones. Although I don't know what order you make it in, because it DOES matter. When you have created the potion, take it into the Watchtower Wizard and ask him to cheap RuneScape Mobile gold enchant it. You'll Get an Anti Dalgroth Potion(3). Head to Dorgeshkan and lender for a huge battle. Inform Oldak you are prepared, and he will lead you to his portal machine. The box will explode.