Location: Earth > The Underworld > Lord's Watch
Requirement: Level 99 and Neophoenix Ship

Scroll to the bottom for cheat guide, top section offers hints that *hopefully* help. :)

Ending #1 - Rewards: Portal emblem and 1 xp

Spoiler

Find the room with the desk. Get the screwdriver and then take the door to the north. At the locked door use the screwdriver to pick the lock and then descend the stairs. Take the door to the right and then step into the portal.

Hints for ending #4 -
-Wandering Room: It's very simple. Overthink it and you'll be lost. Look at the riddle before you enter the room and then simplify it.
-Safe Code: Again, very simple. Look at hint before you try the safe, and look at how the options for each digit of the code relate to the numbers in the hint.

Safe Code

Spoiler

B263

Wandering room

Spoiler

North, North, West, South West

Also, two hints for the whole story:

1. Read the story! You have to know what's going on. Atleast the first time through read it so you can figure out what to do.

2. Don't overthink! There are riddles in this story that seem very complicated but are much simpler than they look. Think simply and you'll be a lot better off.

END OF HINT SECTION

Here are the complete, input by input guides for all four endings. Courtesy of Bunnyz.

Ending #1

Spoiler

East -> Desk -> North -> Descend -> Pick lock -> Door on RIGHT

Ending #2

Spoiler

East -> Desk -> Main Hall -> West -> North -> Search -> Unscrew -> Back -> South -> West -> Stealth Mode -> Key -> Go Back -> Main Hall -> Double Doors -> Sneak Around -> Enter door -> Door 2 -> Chest of Purity -> Golden Chest -> Door 2 -> Cosmos -> Open -> Go through -> Back -> To Throne Room -> Back Through Double -> West -> West -> Stealth -> Pick Up Key -> Back to main hall -> Double Doors -> Sneak -> Enter -> Door 2 -> Chest of Purity -> Obsidian Chest -> Take Ammo -> Back to Throne Room -> Go back -> Throne Room -> Attack

Ending #3

Spoiler

Repeat Ending #2 but choose the sneak kill option and then press the button.

Ending #4

Spoiler

East -> Desk -> North -> Descend -> Pick Lock -> Left Door -> North -> North -> West -> South West -> Enter the door -> Main Hall -> West -> North -> Search -> Unscrew -> South -> Main Hall -> Double Doors -> Sneak around -> Enter -> Door 1 -> Continue x2 -> Exame Security Pad -> B263 -> Go Back -> Throne Room -> Double Doors -> Main Hall -> West -> West -> Stealth Mode -> Continue Searching -> West -> South -> Use the Lyre

Thanks again to Bunnyz for putting this together!!!