It's great to see the stuff that's incoming next week. Beyond Spellcrafting and moving forward, a tree that only provides an ultimate.
Basically, lore-wise, the two southwestern holds of Skyrim are now open to Ebonheart Pact players as well as Veterans of the Aldmeri Dominion and the Daggerfall Covenant.
During this time frame, the Reach is unconquered. Hjalti Early-Beard, aka Tiber Septim has not even been born as of yet, in fact the Soulburst happened 300 years prior to Talos' birth. And it's occurring an extremely long period of time prior to the Dragonborn's defeat of Alduin, Harkon, and Miraak.
Directly adjacent via the Northeast to the Rift and nearly due East of Eastmarch is the Whiterun Hold. This is a massive zone and also borders at its far East, the Reach.
The Reachmen have a presence in ESO already, especially in Bangkorai, and another zone that I can't remember off the top of my head. Needless to say, to figure that the Reachmen would be encroaching into Whiterun Hold is not a stretch. In fact, it would be largely tied to holding back the Reachmen from encroaching into Eastmarch and the palace of the High King of Skyrim. I understand this matters not at all to either the DC or AD thematically, that's not the carrot for them.
Within Whiterun Hold exists the Throat of the World and High Hrothgar. The encroaching Reachmen are impacting the Greybeards and they need everybody's help because the threat looms large. In return for your assistance, they are going to teach you a single shout. Before you say "Why only one?" the first thing you have to realize is that you aren't Dragonborn. Nor were you born with it ala Ulfric Stormcloak.
You are going to pick which shout you will get and it will be an ultimate with a few passives that will bolster your ultimate generation and provide some buffs to you based on your ultimate levels that is largely based upon which Thu'um Ultimate you pick. The overarching goal is to not only provide you with an interesting decision regarding your ultimate, but to also tie a much stronger choice beyond whether you have enough ultimate to use your ultimate or not.
Additionally, there will be some new crafted sets and the zones delves and world bosses will be tied to being group content, but the overarching questing will be tied to solo play, with scaling up if you choose to do them as groups. The delves and world bosses won't be needed to complete the Thu'um quest line, but will provide very high drop rates for really good gear with strong set bonuses.
Whiterun, the city, will have to be liberated from the Reachmen, and at that point the city will be turned into a major trade hub, with more potential guild vendors than any other. The city of Whiterun will have trade guilds and unions in it that will allow you to begin establishing you a resource train to eventually buy a plot of land in Cyrodiil and start feeding supplies and crafters to said spot to begin building your plot. Your plot will only be active on your home campaign and will not be instanced but will be guarded by NPCs you also hire.
Beyond that, the actual Thu'um trees, remember you can pick one and only one, and will have to undergo a weeklong series of quests to change it with a one month cooldown between being able to change it. This is not something that should be easy to change and it should be a commitment you want.
Active choices. The duration and effectiveness of the Active Shouts increases per every 100 Ultimate you have. However, you cannot generate ultimate while they are active and they all provide both an Active effect and a passive buff with a duration based upon the amount of Ultimate spent on the Thu'um Utilized.
Stendarr's Shield:
Fus-Ha-Qah: Force-Mind-Armor
You force all enemies within 20 meters to attack you for 5/10/15/20/25 seconds and decrease all damage you take by 5/10/15/20/25% for the same duration. Taunt portion does not function on player characters but does work on player pets.
Mara's Mercy:
Laas-Shaan-Gar: Life-Inspire-Unleash
You reduce the damage taken of all friendly targets within 20 meters by 5/10/15/20/25% for 2/4/6/8/10 seconds and all of your healing is increased by 2/4/6/8/10% for 5/10/15/20/25 seconds.
Julianos' Knowledge:
Gaan-Lah-Dun: Stamina-Magicka-Grace
Your magicka and stamina regeneration is increased by 10/20/30/40/50% for 3/5/10/15/20 seconds and you gain a shield equal to 100% of your health that lasts until consumed.
Shout of the Unborn Divine:
Fus-Roh-Dah: Force-Balance-Push
The power of Skyrim pulses through you and makes your next 1/2/3/4/5 abilities deal an additional 250 Frost damage, automatically crit, and increases your critical strike damage by 10/20/30/40/50 on those abilities. This works on both stamina and magicka based abilities.
Yes, I'm nostalgic.......
Dismay of Arkay:
Faas-Viik-Mar: Fear-Defeat-Terror
Targets within 20 meters drop their weapons in terror of your Thu'um and are unable to act for .5/1/1.5/2/3 seconds. Afterward, they have a 25% chance to miss you with their attacks for 5/10/15/20/25 seconds. Debuff does not stack from multiple applications.
The Chosen of Akatosh:
Gar-Diiv-Mul: Unleash-Wyrm-Strength
You summon the spirit of The Dragon Aspect to assist you for 5/10/15/20/25 seconds. He deals damage equal to 50% of yours and cannot critically strike. You also divert 50% of the damage you receive to his visage.
The Toils of Zenithar:
Mid-Vur-Shaan: Loyal-Valor-Inspire
All friendly targets within 20 meters of you deal 2/4/6/8/10% more damage, and you deal an additional 1/2/3/4/5% on top of that for 15 seconds.
Passives:
Bargain of the Betrayer: The Gift of Paarthurnax bestowed upon Men, Furries, and Lizards, and Mer let's you deal .025/.05% extra damage resistance/armor bypass but costs .015/.04% armor and spell resistance per point of ultimate you have while the Thu'um is your equipped ultimate. Maximum bonus is 25% damage and spell/armor penetration and 20% reduction in both armor and spell resistance. The damage bonus is a proc and cannot crit. It will display as "Bargain of the Betrayer" and deal additional damage based on the ability that procs it.
Keep in mind that this is written from the perspective that Heavy Armor damage reduction caps will be much higher than they currently are, meaning Heavy Armor tanks won't get slaughtered by the protection decreases.
Calm of the Windcaller: The Greybeard training helps you maintain a calm center while in combat and you gain a boost of .025/.05% of your magicka and stamina recovery per point of ultimate, but abilities cost .015/.04% more per point. Maximum boost is 50% of current stamina and magicka regeneration and 20% cost increases. Additionally, you gain 2/4 extra ultimate per damage and healing you deal, regardless of critical strike or not. Requires a Thu'um ultimate equipped.
The Duality of Akatosh: The power of Thu'um both strengthens and weakens you. You take 2/4% more damage, but you gain 1/2 Ultimate per point of damage that you take.
TL;DR: Magnets.