Exclusive: Monster Train 2: Echoes From the Void first details

Monster Train 2 continues to chug along as one of 2025's best games, a highly-replayable deckbuilder with an ingenious clan combination system. After adding 15 new cards in September's The Lost Arsenal update, the game continues to deliver on its promised roadmap. The second payload of post-launch content is called Echoes From the Void, and it will be arriving November 5.

I spoke with Shiny Shoe game designer Colin Krausnick about the two new bosses arriving in the update, what new artifacts are on the way, and how these new threats will complicate existing strategies.

Main things to know about this update:

• Echoes From the Void is introducing two new bosses: The Fleshweaver, and Stryx and Hallow
• Echoes From the Void is releasing Nov 5, for free
• The Fleshweaver becomes an alternate boss for Arkion, in Ring 3
• Shiny Shoe says: "When Fleshweaver is attacked, it creates a Fleshling minion in the train on the current floor and loses one stack of Mass. Fleshlings have a variety of different gameplay effects based on the variant of the boss. For example, in one variant, Fleshlings spawn with Spikes."
• Hallow and Stryx become an alternate boss for Cael, in Ring 6
• "Stryx & Hallow are two separate characters that fight together. They are angelic twins that fight as one, drawing strength from each other over the course of battle. When one falls, the other fights on with unyielding fury."
• Also coming in this update: new challenges, new mutators, new artifacts (some details below), and new train room cosmetics

PC Gamer: Is there an overall goal that you had in mind with Echoes From the Void?

Colin Krausnick, game designer: Echoes from the Void is focused on new run variations and expanding overall content to increase replayability. However, there are some seeds being sown for what we are developing for the next update coming after Echoes from the Void.

Arkion and Cael already represent two major tests for players in Monster Train 2. What are your general or specific goals in introducing two new bosses that can replace them?

Our main goal is to add more variety to each run in a way that feels fresh and different from the current flying bosses. The new bosses serve as a good way to introduce new mechanics earlier in the run, such as how Stryx emulates a certain Titan.

As you say, other than the Titans finale, Stryx and Hallow are the second "split" boss. Is this something you wanted to play with to prompt players to make difficult decisions about unit placement & rooms?

Yes, it was actually something I was looking for a way to do in the original release and found an outlet for in this content update, essentially a simpler version of the Titan encounter that embodies their mechanics and themes.

Subverting the usual enemy behavior (in this case by looping back to the first floor rather than ascending to the Pyre Room) is interesting, but must be done with some care; if it’s overdone it can feel more jarring than fun. People often have their preferred playstyles, and if we deviate too much it can lead to frustration.

What variations are there for Hallow and Stryx?

Sure! Each variant focuses on different triggers for the bosses which buff their counterpart. The “Inevitability” variant is tied to more consistent triggers of Loop and Resolve. “Doombringers” focuses on triggers that are easier to play around—Slay and Incant. “Bloody Harvest” has the hardest triggers to avoid in Revenge and Siphon. The enemies found in the encounters serve to help these bosses achieve their battleplan, such as Energizing Flautists granting haste to Stryx to help her Loop faster.

Other than their status as a pair of bosses, how will Hallow and Stryx represent a different kind of threat compared to Cael?

Their threat comes less from the other enemy units in the encounter and more from the player needing to stop them from scaling out of control. If you don’t avoid them buffing each other, they can reach extremely dangerous levels. In general there is less damage coming through to the Pyre compared to Cael. To win you will need to take them down early; if they reach the Pyre, it’s usually game over.

It looks like Hallow is giving Stryx +30 HP per incant, am I seeing that right?

Yes, the main theme around the fight is about these cursed Angelic Twins being connected and increasing the power of each other. This ties into the other major new mechanic in this fight, in that if you defeat one before Relentless, the other one “enrages” and starts Relentless right away on the next turn, along with absorbing some of the innate power of the other.

With The Fleshweaver, was the intention to give the boss a kind of different kind of blocker?

Sort of. One of the intentions was to find a way to introduce more attrition damage to the Pyre without totally taking it out. That goal changed somewhat over time, as there were some weird timing issues with these new enemies appearing on the top floor and immediately ascending into the Pyre Room which felt bad overall. So we went with a version of these new units that start Rooted and thus don’t ascend until the next turn, giving more room for counterplay.

How will The Fleshweaver represent a different kind of threat compared to Arkion?

The threat of The Fleshweaver comes from figuring out how to “carve” off stacks of his Mass buff without overwhelming yourself too early. The general idea is that the boss gains power the more stacks of Mass that it has, and you can remove them by hitting the boss but it will spawn a Fleshling enemy. If you spawn too many too early they can do a bunch of damage, but if you don’t create any, then during Relentless the Fleshweaver will be stronger due to the attack it gains per Mass stack.

Can you share the variations that players will encounter for The Fleshweaver?

The variations don’t change the Fleshweaver much, but they do change the Fleshlings it creates. Corrupted Mass causes the Fleshlings to corrupt whatever slays them, Spiked Mass gives them spikes, and More Mass adds additional stacks of Mass to the Fleshweaver as well as some extra power to each Fleshling.

Sounds tough. Can you share any of the new artifacts that will also be added in this update, which will hopefully help us deal with these new bosses?

Yeah, sure! There are a number of new clanless and Celestial Alcove event artifacts in this update. Here are two examples.

One is called Departure Manifest. It allows you to play Non-banner units during your Deployment Phase.

This second one is called Abyssal Prism. It has a wild effect that applies the first spell you cast each turn onto all other friendly units on the floor. This can be good or bad; you must be careful. It excludes “move” effects, like Advance, because we found they are too hard to reason about what the outcome should be.