Hi,
following suggestions are only for Ego Draconis, neither for FoV nor DKS.
if you have only ego draconis installed the best way to survive the final battle is to (in case you are a battle mage-paladin combination):
upgrade your skill for 2-handed swords and take a good 2-hand sword (e.g. after the flying fortresses)
upgrade bleed to 10
upgrade fireball to max
upgrade potion efficiency to max
and upgrade the demon to 5-6
Before the battle started I had 29 skill points to spare, so I tried the best combination.
Summon the creature and the demon first, then attack with fireballs until the demon vanishes..
And keep running!
But I have to agree, after installing the addon the fight was almost impossible as the skill for 2-handed swords was almost worthless.
Also after installing the addon my creature was gone, I had to wait for a moment to get it activated again.