What's wrong with this battle?

[Alneyan]

Amon Hotep could be nice in the Helmet department. It also is expensive. Very much so. Still, you might find some use for 50% fire resistance, 30 natural protection and Awe +5. Besides, it looks good. Crown of the Ivy King might be another option, and a much more reasonable one; it would give your Pretender some regeneration.

In the upscale department for armours, there is always the Robe of the Magi. It would work out much better than your current Rainbow Armour, but it is, of course, much more expensive (and finding the right mage could be troublesome, if you haven't been blood hunting).

The Stone Bird could help you with attacking, though I suspect its "lessen defence of the target" effect happens after your main weapons. That one aside, a Crystal Heart/Elixir of Life comes to mind, if you are concerned about your Pretender biting the dust; I know I like too much Immortality, the Armour of Virtue and things of the like. Well, live and let live and all that...