The Stygian Abyss update will be bringing a lot of updates that are going to be fun. Below are listed more in depth but not limited to.

These creature are limited to Dealers of Destiny so the stats would not be the same as on any other UO server, but they are pretty close.

Each creature has the chance to drop one of 25 artifacts that have been created for this server.

The Artifacts are:
Abandon Axe
Animated Legs of the Insane Tinker
Basilisk Hide Breastplate
Boura Tail Shield
Burning Amber Ring
Cavalrys Folly
Defender of the Magus
Demon Bridle Ring
Demon Hunters Standard
Draconi’s Wrath
Eternal Guardian Staff
Ironwood Composite Bow
Jade War Axe
Night Eyes
Protector of the Mage
Resonant Staff
Shroud of the Condemned
The Impailers Pick
Token of Holy Favor
Torc of the Guardians
Vampiiric Essence
and Venom

Three new legendary items are coming to the server.
The Legendary Ring of Health, a Legendary Cloak and the most excited Legendary Aegis shield. This already has some nice stats to it before you get it.

The way you will be getting these is through a new system where you will need to find mystic orbs. These can be found on many creatures, plus the new renowneds will carry some. You will also be able to buy Mystic Orbs in case you feel its taking time to get them.

Player Stats will increase to 450 cap. This will allow you to reach 150 on each of your strength, inteligence and dexterity.

A new evolution creature is coming to the server. The Korpre is a wonderful little creature. These look like slimes and evolve into three different creature.

Each Korpre starts as a slime, but each grow into different types each with their own skillset.