To access Plane of Souls, you must have completed the Chain Quest: Quests#Chain Quest. This is an end-game zone with powerful monsters and increased skill chance. Home to special beasts that can destroy of upgrade equipment.

Bonus

Increased Skill Chance -- 1+Monster # counting down the list

Difficulty

Stronger monsters than Dullahan

Requirements

Chain Quest: Quests#Chain Quest

Locations

Larger Money Bags
5,6 - More credits drop
No Fools or Elites
4,3 - No Fool or Elite mobs will spawn
Time Temporal Entrance
6,2 - Must have completed Doc Quest (see Quests#Doc Quest)
Lake
6,5 - Obtain Fishing Skill and chance to catch Jedi Fish (x500 skill gain for 4 hours)
Trinket Shop
6,9 - Buy/Craft Trinkets