Скачать или смотреть DA:O Warrior-archer with crossbow & bombs. Gaxkang the Unbound nightmare solo.

This video features my solo completion of the Gaxkang encounter on nightmare (shown at 22m 00s) difficulty,

The point is to get pieces of armor & accessories with attack dodge chances to stand out against Revenant form. As many pieces as you can.
The other problem is to find a way how to quickly do a lot of damage to dangerous Arcane Horror. I used bombs (all 5 types) because crossbow is not enough (all crossbows are rather weak and underpowered weapon in DA:O).
Ice Salve, Spirit Balm, Mental Fortress and Holy Smite also were very usefull in this combat. Ice bolts and fire bolts are helpful but i didn't have them enough.

Here is my equipment:
Sailor's Crossbow (gives Rapid aim)
Helm of Honnleath
Repeater Gloves (give Rapid aim)
Battledress of the Provocateur (gives +15% chance to dodge attacks)
Cailan's Greaves (give +20% chance to dodge attacks)
Cinch of Skillful Maneuvering (gives +10% chance to dodge attacks and +10% spell resistance )
The Spellward (gains +10% chance to dodge attacks and +30% spell resistance)
Lifegiver
Harvest Festival Ring