Voldemort is a level 777 Boss with 66,666 Hitpoints. The only effective methods of dealing damage are Ranged and Magic. Melee will not do damage to him. He has multiple unique attacks, including the following: Magic, Ranged, Lightning, Water, Fire, Black Magic.
You can fight Voldemort by typing ::joinraid1
During the fight
Voldemort starts off with 1,000 mana points. Every attack will detract between 1 and 200 mana points, it will be completely random with each attack. When Voldemort's mana reaches 0, the next attack he will do is a charge attack, which will heavily drain your prayer. Note: most of the blue fire attacks will also drain your prayer or do severe damage. The closer you stand to the boss, the higher the chance you have of getting attacked by his barrier spells. These spells consist of elements that can have a special effect on you; ice can freeze you, fire can burn you, and lightning can drain your prayer.
In order to receive loot upon killing Voldemort, you will need to be among the top 3 damage dealers.