Swarm Disaster is an expansion to the Simulated Universe mode available in Honkai: Star Rail that introduces new enemies, Paths and a lot of rewards. You can access the mode in the SU main menu and while the premise of the mode is similar to the base one - with its roguelite nature - it's actually a lot harder and can be considered the hardest content available in the game.
Partially because on the highest difficulty (there are 5) available in the Swarm Disaster you will fight against level 95 enemies. To compare to, in the Memory of Chaos, the last stage features level 90 enemies which translates to them having more HP, but also you doing less damage since the damage formula takes into account the difference between your character levels and the enemy you face.
The Swarm Disaster mode features a separate progression and skill tree that gives your characters free stats for doing various challenges - which is another change compared to the base Simulated Universe skill tree, where you just had to play the mode to unlock the nodes. And we strongly suggest to focus on progressing down the tree, because it will make the mode much easier. You can check all available bonuses you can obtain there further down the guide in section dedicated to them.
On top of great rewards that you can obtain in the mode (including 4500 Stellar Jades) you will also be able to unlock the Path of Propagation in the base Simulated Universe. The Path enhances the Basic Attacks and also helps with Skill Point management which makes it perfect for the recently released Imbibitor Lunae and Qingque.
When you first enter the Swarm Disaster mode, you will have to pick one of the available Paths and similar to the base Simulated Universe not all Paths are unlocked when you start playing the mode and you need to progress through the difficulties and story to gain access to them. At first, you will only have access to the Destruction path (during tutorial) and shortly after you will unlock Preservation, Abundance and Hunt Paths.
The Path you choose will not only affect the Blessings you will want to focus on and your playstyle, but it will also impact how you interact with the Board and Domains - so the main mechanism of the Swarm Disaster mode.
Here's a list of all available Paths and their bonuses:
When the first or second Plane begins, surprising effects will be applied.
When allies enter "Domain - Boss" or "Domain - Boss: The Swarm", obtain 1 random Happiness. For every domain that allies pass through, the Follow-up attack DMG dealt by all allies receive random stat increases.
The Elation Path is perfect for characters with Follow-up attacks. Moving through the game board will grant you a permanently stacking Follow-up attack damage bonus - though keep in mind that the amount this bonus increases per movement is random, so there's a RNG element tied to it. Use your Dice to apply Happiness to tiles with undesirable domains - Happiness has a chance to transform tiles positively e.g. into loot domains or negatively e.g. into Swarm Domains.
When the first or second plane begins, turns 2 Domain(s) into Domain - Elite.
After achieving victory in Domain - Elite, obtain an extra 1 Blessing(s). For every battle won, increases DMG dealt by all allies by 8%.
Destruction is generic Path that offers global DMG% increase for your entire team based on how many individual enemies you slay within the entire run. Focus on moving to Combat Domains to stack up your continuous bonus and use enhancement Dice to upgrade Elite Combat Domains you intend to path towards to. When rolling your Legendary Dice use it on an Elite - preferably one that is enhanced saving you time and allowing you to take a different route with more opportunities.
Any character can work here.
When the first or second plane begins, generates 1 extra Blessing Trotter and 1 Curio Trotter beacons.
Blessing Trotter: There will be a Trotter with this Beacon in the Domain. Defeat it to obtain additional Blessings.
Curio Trotter: There will be a Trotter with this Beacon in the Domain. Defeat it to obtain additional Curios.
Every time allies move to a Domain, all Domains currently with the Blessing Trotter or Curio Trotter will swap their positions with an adjacent Domain. For every Trotter defeated in battle, all allies' CRIT DMG increases by 30%.
The Hunt Path is the strongest offensive Path for characters that can utilize critical strikes. Slaying Warp Trotter encounters will grant you stacking Crit DMG bonus, so focus on using your dice to generate, lock down and move towards Warp Trotter domains - but be aware that the little buggers don't like to stay in one place and will teleport around the board.
Any crit-based character can work here.
When the first or second plane begins, applies Mercy to 2 random Domain(s).
When using Audience Die: Abundance in domains with Mercy effect applies, the countdown timer will no longer be reduced and have 1 added to it instead. This continuous effect will conclude after triggering Planar Disarray.
Countdown is reduced by 2 extra count(s). When entering Domains with the Mercy effect, this effect is changed to adding 1 counter(s) to the Countdown. Every Countdown counter increases all allies' Outgoing healing by 5%.
Abundance is a passive path focused on gathering many more Blessings than any other Path thanks to the ability of completely ignoring the countdown. For each stack of countdown remaining, players will obtain increased % Healing, offering a large initial defensive bonus compared to other paths. Focus on spreading as much Mercy as possible and only navigating through domains with Mercy already on them. Be aware that choosing a domain without Mercy will cost 3 countdown but choosing one with Mercy will add 1 countdown to your remaining total.
Due to the nature of the Path, it's a generic path that can work with any damage dealer type as long as you have a Healer in the team (which you will need either way). It's slower than others, but unless your characters will be one-shot, you will - eventually - conquer the mode.
When the first or second plan begins, turn 2 random Domain(s) into "Domain - Blank".
Domain - Blank: Nothing will happen in this Domain.
A "Domain - Blank" will be replaced with a Domain of a random type when allies enter it. For every "Domain - Blank" that allies pass through, DoT dealt by all allies increases by 18%.
The Nihility path is ideal for Damage over Time compositions offering a stacking continuous effect that boosts DoTs massively. Re-roll your Dice aggressively to convert as many domains into Blank Domains with the goal of converting the majority of Domains.
Activating conversion Dice outcomes will remove that option from being rolled and once all of Domains are converted the only remaining Dice options will be your legendary effect and one other granting you massive rewards in which you should priorities moving through blank tiles at this time.