The strategy to efficiently find and farm Uber Sung Lee is made possible within the Ether Tree allowing you to locate and access theEternal Battlefield with a 100% Chance in anyOverworld Map.
This is made possible by taking the Summoner of Battlefields node in theEther Tree which guarantees at least 1x Eternal Battlefieldspawn in whichever Overworld Map you happen to be in.
Note:I recommend Act 1 maps for less danger whilst locating the Eternal Battlefields
The Never Ending Conflict node is taken to grant a 25% Chance to restart the Eternal Battlefield Encounter when it ends enabling faster Battlefield FragmentFarming.
The Mirror of Eternitynode is taken to grant a 25% Chanceto spawn a second Eternal Battlefield Encounter enabling faster Battlefield FragmentFarming.
TheKey to Battle node is taken to grant a small chance to drop a full x50 Stack of Battlefield FragmentsorInfernal Battlefield Fragmentsdepending on if you are in are Hell Difficultyor Inferno Difficulty.
If you feel you are strong enough you can also take the Mirror Execution node which grants a25% Chance to spawn 2x Uber Sung Lee 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 Eternal Battlefields as quickly as possible as this is required in order to farmUber Sung Lee.
Note:I recommend Act 1 maps for less danger whilst locating the Eternal Battlefields
This is where you can farm Battlefield Fragments or Infernal Battlefield Fragmentsas well as gaining access to the Eternal Battlefield Boss Portal.
Uber Sung Lee
Once you havex50 Battlefield Fragments or Infernal Battlefield Fragments you can locate enter the Eternal Battlefield.
Once you enter the Eternal Battlefieldyou a small zone to navigate containing a bunch of enemies and a small arena where Sung Lee resides typically in the Bottom Left orBottom Right of the map.
There are a few moves that Uber Sung Lee uses that you will want to be careful of if you aren't able to instantly delete him which would require a very high amount of damage since he has around141 Billion HP in Inferno Difficulty.
These include:
1st Summon Weapon(A long ranged fan like multi-flail ranged attack)
Earthquake (Jumps in the air and spawns a flail at your position on landing if you are on the ground)
2nd Summon Weapon(A long ranged fan like multi-flail ranged attack)
Rain of Doom(Spawns Flails from the sky leaving burning ground on the floor where they land)
Possible Drops
There are a number of Heroic Items that can drop herethat are all highly sort after in the endgame.