Some random people i know alot about and they help you

The Adventurer [Player]
An unnamed adventurer who arrives at a rogue encampment in the aftermath of Diablo's movement to free his brothers. The adventurer gradually becomes stronger while searching for the cause of the destruction. He/she travels throughout the land of Sanctuary, eventually ending in the depths of hell and facing off against the Lord of Terror himself.

Deckard Cain
The last surviving member of the Horadrim clan, Cain is an old man who supported the adventurers in Diablo with information regarding anything, from tips to demons. He is also the only survivor when Diablo destroys Tristram, the city where Diablo originally resided before he was killed, and is saved by the adventurer. In Diablo II, he travels with the adventurer and offers hints on how to proceed with quests and can identify items, as well as information of the history of Sanctuary. He has been comfirmed to appear in Diablo 3.

Tyrael
Tyrael is an Archangel who rebelled against heaven in order to teach the Horadrim how to seal the Prime Evils's souls into soulstones, thereby trapping them for eternity. He is captured by Baal after he fails to stop Diablo from releasing Baal and eventually freed by the adventurer. He comes back when the adventurer reaches the Pandemonium Fortress, the last bastion before Hell, to offer his protection.