Mephisto the lord of hatred

Mephisto uses the skills, lightning, charged bolt, blizzard, frost nova, poison nova and skull missile (very deadly).

On hell he got Cold, fire, lightning and poison 75%, Magic 50% and Phys 20%. Arround 95k life

He got very good loot table and go up to Cham rune

Best way to farm Mephisto.

If you're a begginer go /players3, if you´re godly geared go /players7. 

Find a good map of durance level 2 (Entrance of Durance level 3 very close to waypoint of Durance level 2).

Starting the run!

Start in act IV, telekinesis the waypoint and go to Durance level 2, teleport into the entrance of durance level 3.

The beginner approach.

Teleport to Mephisto and lure him till the river, positioning yourself down of the redline, he can´t reach you, cast yours spells and kill him, get the loot and go trough the red portal.

When in act IV save and exit. (REPEAT)

The pro approach.

Teleport up to the redline let your hireling tank him, kill him there, take the loot, teleport and pop the Mephisto superchest (decent runes patterns), teleport down and go to the red portal using telekinesis skipping the bridge of bones animation. 

When in act IV save and exit. (REPEAT)

Killing him above the redline you can telekinesis the red portal

Mephisto Superchest

The Token of Absolution

The token of absolution is an item of diablo 2 lord of destruction, when used you will reset all your stats and skill points. 

To make that item you will need use the Horadric Cube merging some essences (1 of each type).

(Only on Hell mode)

The Twisted Essence of Suffering is dropped by Andariel or Duriel
The Charged Essence of Hatred is dropped by Mephisto.
The Burning Essence of Terror is dropped by Diablo
The Festering Essence of Destruction is dropped by Baal.

On battlenet this item have some trade value. 
Sometimes you make a mistake when distributing the skill points, or maybe you just want change your build.