The strategy to efficiently find and farm Uber Reaperis made possible within the Ether Tree allowing you to locate and access theShadow Realm with a 100% Chance in anyOverworld Map.
This is made possible by taking the Summoner of Shadows node in theEther Tree which guarantees a Shadow Realmspawn in whichever Overworld Map you happen to be in.
Note:I recommend Act 1 maps for less danger whilst locating the Shadow Realm portal
The Key of Shadows node is taken to grant a small chance to drop a full x40 Stacks of Dimensional Shards or Infernal Dimensional Shards depending on if you are in areHell Difficultyor Inferno Difficulty.
If you feel you are strong enough you can also take the Twice the Shadows node which grants a 25% Chance to spawn 2x Uber Reaper to fight at the same time allowing for double rewards if you can beat them both.
Overworld
It's best to run a map that is easy for you to traverse and quickly navigate with low risk so that you can locate the Shadow Realm portal as quickly as possible since this is where you want to be in order to farmUber Reaper.
Note:I recommend Act 1 maps for less danger whilst locating theShadow Realm portal
Uber Reaper
Once you havex40 Dimensional Shards or Infernal Dimensional Shards you can locate Asheenwho will always spawn inside the Shadow Realm and opens a door to Reaper's Breach.
Once you enter the Reaper's Breachyou have to run a short way Northto reach the arena where you face off againstUber Reaper.
There are a few moves that Uber Reaper uses that you will want to be careful of if you aren't able to instantly delete her which would require a very high amount of damage since he has around141 Billion HP in Inferno Difficulty.
These include:
Death Coil(Omni-directional projectile attack)
Pentagram Slam (Big AoE slam - One shots if not avoided)
Scythe Strike(Perpendicular projectile attack that deals big damage)
Shadow Skull (Homing skull projectile attack)
Execution (Criss-cross scythe projectile attack)
Shadow Lantern (Makes Uber Reaper invincible until dead and heals him if not killed in time)
Possible Drops
There are a number of Heroic Items that can drop herethat are all highly sort after in the endgame.