I beat Amdusias at level 14 (on
nightmare difficulty mode) and is for sure possible
But I must say I thoroughly prepared myself & take my time.
What I do?
At that time I had (and still have) a Creature that use Fireball (skill L6), so not so good against Amdusias with his killing Explosive Arrows(!!) .. better is to have a Melee head for your Creature (with for example Fatality skill), but I had not found some head at that time so I decided not to use my Creature.
But I was wearing the Amulet of the North that has the skill + 1 to Hide in Shadows and I put 1 extra point in this skill (to be sure) so I had more that time enough to run to the dragon scales, take them and run back. After the cooldown time of Hide in Shadows I go to transform Amdusias out of his Dragon form and at the end of the conversation I use again Hide in shadows and run away from him.
At the time my mana & HP are back OK I first make a seperate save game.
After that I drink potions, the best I can at that time :
Lesser Strength, Lesser Intelligence, Lesser Dexterity and a Minor Full Resistance.
I summon my Ghost (L 5/5), and had also 1 point in Summon Mastery, so he can help me in battle and HEALING me !
My hero on that moment is wearing the FULL Armour Set "Defenders of Aleroth" with a great Mace I enchanted it with a + 20 to Magic Damage. My Intelligence was already around 15/18 I believe and with that extra Intelligence potion even more so my Mace did around 125 Magic Damage !!
Also wearing a Bracelet with + 2 to Rush Attack.
Then I use Hide in Shadows and run to Amdusias and begin to melee attack him !
Use Rush Attack because Amdusias was "trying" to use his bow (I think because my Ghost attack him with a Fireball!) ... after that Amdusias take his sword and use it to the end of his life ! (but it was a very fast/short fight)
In between I only must use quickly 2 Lesser potions : Rejuvenation and a Healing potion to be SURe to survive ... my Ghost, I don't remember he must do much ... because using the Mace of the Defenders of Aleroth was a very fast trip to kill Amdusias!
But without Hide in Shadows ... hmmm ... my HP was already more than 500 HP ... maybe, but I'm afraid NOT, but maybe just with running and using
Rush Attack and without Hide in Shadows it is also possible to defeat Amdusias ... you can try that.
Good Luck with killing Amdusias !
Joram (& Jurdenson)