Okay so I thought about Sauron's role in his snake form and I figure we use the Were-Wyrm model from BFME2 for Sauron's snake form--but we mold it to look like the Basilisk off of Harry Potter:
https://vignette.wikia.nocookie.net/harrypotter/images/9/9a/Basilisk2.PNG/revision/latest?cb=20090822212528Gorthaur shows on his Palantir to have four forms, but the fourth form is an empty slot stating what we already know as gamers. This is a wasted slot:
"Once the One Ring has been recovered, Gorthaur takes the shape of a dreadful dark lord and increases his power. He becomes the Sauron that has made Mordor known and begins rampaging through the map."
Therefore I suggest Gorthaur to take his canonical form of a serpent like he did in the First Age and become a mass slayer. He would move like the Were-Wyrm and attack like a Were-Wyrm in BFME2, instead of fire though, he attacks with a plague, corrosive, or venomous breath attack--maybe his breath does 260-300 damage.
I have reworked his abilities and are as follows:
1. Revert back to Gorthaur.
2. The Serpents will stop you: Basically an evil version of Radagast's weed/tangle roots power. Except these are deadly spiny roots.
3. Shed Skin: Sauron sheds his old serpent form and now has better armor. +50% armor boost.
4. Poisonous Plague: This acts and functions exactly like the plague spell on Angmar's spell list.
5. Venomous Will: Converts enemy units permanently to Mordor, but on Heroes it does the same affect as hour of the witch king.
These powers are canoical and I could have seen Sauron trying to use these on Huan in an attempt to get away. The Venomous Will represents Sauron's powerful dominating will and how he broke Saruman and Denethor through the Palantir.
I disregard placing Annatar as a Defensive stance for the Necromancer--I feel something else should be thought of--but I am open to new ideas.
I hope you all liked this and read this. I think this would be canonical and funtion correctly. Let me know what you all think.
--dkbluewizard.