Awesome to see a Kresh list, I feel like he's pretty underplayed. I have a list of my own you might take a look at (Blood for the Bloodbraid!, though it might be trying too hard for what you're aiming to achieve here (for example we both have Elemental Mastery, but I run it with Purphoros, God of the Forge because as long as Kresh has a high power the two win on the spot, my list has lots of stuff that wins very quickly once Kresh reaches critical mass). Another card that can go off with Kresh almost without support is All Will Be Counters, because you can just machine gun down the whole board if you can kill something big to kick things off. You also might find a use for Ezuri's Predation, it is a lot of mana, but the effect is such that you almost always end up with a huge Kresh and a few 4/4s to chump with, it plays better in Kresh than in most other lists. Oh, and incase you want to one-shot someone you might try Mandate of Abaddon, if Kresh is bigger than everything a particular player has out then you play this and one-shot them, is that a reasonable play for your meta?

If you want any specific help with Kresh, feel free to ask, he's an incredibly fun Commander to build, there are just so many cards that are absolutely bonkers together (and with Kresh).

Changeling Outcast isn't from Lord of the Rings, but you can put Army counters on it because it's also an army. You can also try Mistwalker and/or Taurean Mauler, though they aren't as evasive.

Cool list, always neat to see a strong Sauron deck!

He's not heavily played, but Kresh the Bloodbraided can do some absolutely nutso things when he's big enough, and the deck often has some control elements (especially vs creatures, the deck wants to kill off everything but Kresh typically). It can be built on a budget (for Casual play) or as a High Power deck. On a budget you run all of the Merciless Executioner effects you can find, and at higher power you'll still run a bunch of them, but you'll also have Dictate of Erebos effects. Rite of the Raging Storm by itself turns Kresh into a huge body, and it's easy to include lots of Flings/Chandra's Ignition/Jarad, Golgari Lich Lord to win, but you can also use stuff like Mandate of Abaddon to wipe the board and one-shot someone, there are a TON of cards that play very well with Kresh, and people probably aren't familiar with the deck at this point.

Another option might be Azorius Control, Azorius is a great pair for wipes, removal and countermagic, meaning you can deal with problems, both for yourself as well as the table. I guess you might go something like Shorikai, Genesis Engine and play any vehicles that don't suck? You can freely wipe your pilots without risking your vehicles, even without things like Teferi's Protection. The card draw Shorikai offers can really help you dig, and it synergizes with untap effects.

My final idea would be something like Sauron, the Dark Lord, Grixis gives you a lot of control options, and Sauron makes you a big honking army very readily, and fwiw you can make an evasive Changeling (like Changeling Outcast) your Army in place of a token. Grixis struggles a bit vs certain types of permanents, but you can certainly pressure people and have input as to what stays around.

Oh yeah, just thought of a bad idea I've never gotten around to testing, but you might be able to build Optimus Prime, Hero  ^Flip with all the Jeskai wipes you can find? Optimus can 'survive' a wipe, so as long as you can give him Haste somehow you can swing each turn vs a cleared board, wiping whenever anyone gets anything relevant out. Would it be obnoxious? Incredibly so. But I think it could work, especially since you have Red for various good Haste sources. You probably need lots of things to protect Optimus from Swords effects, including a smattering of Blue counters that are either free or cost {U} so you can hold them up.

Taking a look at other people's ideas, I support Karazikar and Breena, both seem like great fits!