You should be well equipped before you fight. The top listed of recommended items will be dragon warhammers, elder mauls, Amulet of torture, Ava's assembler, Elite void top, Elite void robe, Zamorakian hasta, Avernic defender, Dragon javelin, Void knight gloves, Primordial boots, Ring of suffering, and Dragon warhammer.
Preparation for Challenge Mode
You need 90 Combat, 90 Void, 55 Farming, and 78 Herblore before you enter the Challenge Mode to fight the fierce bosses. The difficulty scaling will rise with the overall team combat level, but a team with the minimized Combat level surely will not win. On the contrary, the higher the team Combat level is, the more likely you will win.
How to kill bosses and Win OSRS Metamorphic Dust
You have to find the weak points of the bosses. Tekton’s attacks have a small delay before they hit. You can run to corners to avoid hitting by his standard attacks. Killing him will require the use of dragon warhammers and elder mauls.
When fight Vespula, split your team in two. One focuses on collecting the blossoms and preventing grubs from turning into soldiers. The rest of the team focus on damaging Vespula, which can be done by roughly 2-4 attacks on the portal when Vespula lands.
You can run away or beneath Vasa Nistirio to avoid its standard attack. You can attack it with Ghrazi rapier and stop it from healing by damaging the crystal it heads to.
Zamorakian hasta is recommended to fight Vanguard. You can slowly damage each Vanguard, causing them equal damage to prevent them from healing. While they are out of their shells, you can kill them by damaging their maintenance.
Zamorak godsword or Ice Barrage will be recommended to stop small Muttadiles from eating from the meat tree. After it dies, you will need Protect from Ranged to protect your team while killing the boss.
You need to destroy Great Olm’s left hand with melee attacks, and his right hand with magic in phase 1 and 2, then prevent Olm from performing any special attacks until it get killed by the falling crystals.