PoE 2 The Last of the Druids: Content Livestream Summary
Overview
The Druid, Shapeshifting & Talismans
The Druid is the first strength and intelligence hybrid class being introduced to Path of Exile 2, starting in the north-western area of the passive skill tree. The Druid is a class that's focused on shapeshifting and nature spells - there are 21 new skills to use in patch 0.4, and over 30 new support gems.

The Wolf form
Druids utilise their weapon slot to equip Talismans, items that allows them to select the type of basic shapeshifting attack that they wish to use from a choice of three forms: Bear, Wolf and Wyvern. Using this basic attack will transform you from human form to the form of your chosen shapeshift. There's no delays or cooldowns for shapeshifting, and using a normal spell will automatically transform you back into a human.
Selecting the basic attack of a form on your Talisman however does not lock you out from the other forms - you're free to choose any other specific abilities from other forms, and using a form ability will automatically transform you into that form with no delay. That means you can create a build that uses all three forms if you wish!

The Bear form
Each shapeshifting form comes with its own advantages and disadvantages - the Bear is slower but more sustainable, and has access to large slam abilities. The Wolf meanwhile is much faster and agile, utilising quick attacks with high mobility and a focus on cold damage. The Wyvern has access to much more utility and combines the power of the elements, using fire and lightning breath attacks, and enabling special interactions for the Druid's nature spells.

The Wyvern form
The Druid will have access to two new ascendancies in patch 0.4, with a third coming in the future.
The Shaman is an ascendancy that specialises in empowering nature spells using rage. Druidic Champion is a notable that the Shaman can choose to make rage also grant more spell damage. Meanwhile, the Shaman will also be able to unlock additional power from socketable runes, making them grant an additional exclusive modifier.
The Oracle is a master of foresight, being able to see the future with immense precision. This ascendancy is able to see a vision of a future boss, providing a moment to be able to deal damage to two entities before they merge into one. The Oracle can also access nodes on the passive tree that cannot be obtained by any other class, but they will need to spend ascendancy points on The Unseen Path notable to do so.
Fate of the Vaal League Mechanic
Patch 0.4 will introduce a brand new league mechanic to Path of Exile 2: Fate of the Vaal. Path of Exile 1 players will recognise many of the themes of this mechanic from the Incursion mechanic. Fate of the Vaal allows players to build their own Vaal temple, with the ability to move rooms and paths and position the layout exactly as you wish, before running the temple for exclusive rewards.

A Temple Console
You'll be able to find Temple Consoles in areas when playing within the Fate of the Vaal league. These consoles are surrounded by monsters that must be sacrificed to empower the device. Interacting with a console will grant you the ability to place six rooms toward the finished temple, before letting you enter the temple to reap its rewards.
Rooms can be placed in specific layouts to upgrade their level, improving rewards but making the temple deadlier. However some rooms have very attractive, exclusive rewards that cannot be found elsewhere. For example the level 3 room Locus of Corruption will allow you to corrupt an already-corrupted item to potentially add an additional corrupted enchantment modifier to it. Be careful though, it may destroy the item instead!

Tier 3 Corruption Chamber
Another powerful reward found in the temple will let you modify a unique item unpredictably, replacing one of its modifiers with a new one. If you're lucky, you may be able to replace one of the downside modifiers that unique items often have with a strong upside, potentially creating an incredibly powerful item that's truly unique.

A Soul Mantle unique with a replaced modifier
The Architect of the temple is in a room that's visible from the beginning. You need to make your way to the Architect by pathing rooms toward their chamber. Defeating the Architect in a temple will allow you to place a special room: the Royal Access Chamber. Seeking out this room in the temple will provide a portal and the opportunity to face a new pinnacle boss: Atziri, the Red Queen.

Atziri, the Red Queen
Endgame Updates
Although endgame was initially planned to be the main focus of patch 0.4, many of the endgame changes that were planned did not make it into this update as they weren't finalised in time. However, there are still some important endgame changes coming in The Last of the Druids.
Maps will no longer be able to be crafted with desecration modifiers from Abyss content, or distilled for extra juice from Delirium content. Part of the juicing lost from this change has been added to tablets, which can now be corrupted to obtain additional corruption modifiers, and can even be improved to rare rarity using normal currency as long as you've defeated The Arbiter. These changes should largely improve the time spent preparing maps in the endgame.

A rare Tablet in 0.4
Monster difficulty and rewards are also being addressed in patch 0.4, with a focus on a lower amount of monsters that are generally more difficult and more rewarding. Monster haste modifiers on waystones have also been nerfed. The goal of these changes is to remove some of the monster swarming in the endgame, and attempt to provide more meaningful encounters.
Delirium fog is also being toned down so that there's a lot less grey on the screen, providing better visual clarity and letting you enjoy the beautiful colours of the game once more.
Abyss Goes Core
Abyss will become a core league mechanic in The Last of the Druids. You'll be able to find Abyss randomly on maps in the Atlas, but you'll also have the opportunity to find Abyss Tablets that you can use to forcibly add Abysses to your maps to allow you to target farm this mechanic for its powerful crafting elements.

Crafting an Abyss Precursor Tablet
There's also an Abyss-exclusive atlas tree that you can obtain points for by completing Abyss encounters and defeating Abyssal bosses. You can invest your points into simply multiplying the amount of Abyssal monsters that emerge from Abysses, or spec into more exclusive rewards, such as the interaction of Rogue Exiles with Abyss pits. You can even invest into the chance for the completion of an Abyss in maps to result in a nearby map being overrun by Abysses.
Balance Changes
The Last of the Druids update will include many balance changes to improve the variety of endgame builds. Over 80 existing unique items are being improved, with a large focus on endgame uniques that can enable new builds. There are also some new unique items in patch 0.4, as to be expected with a new league launch.

New Uniques in 0.4
There will also be a large balance pass on existing ascendancies, with some being completely overhauled and others receiving numerical balance. The Smith of Kitava for example is getting a large revamp in The Last of the Druids update.

One of the Smith of Kitava's new notables
Skills and the passive tree are also getting some attention, with over 90 active skill gems being updated, and over 250 new passive tree nodes being added, many of which will be focused in the strength and intelligence area of the tree where the Druid starts.

The updated Passive Skill Tree in 0.4
Performance Fixes
Fear not, some performance fixes are coming in patch 0.4! The changes should result in 25% higher framerate on average, and the updates should improve console game performance the most.
GGG also acknowledged that performance is a major issue, and they'll be looking to make additional updates in the coming months.