Monster Train

This achievement requires that you end a run with zero cards in your deck. No spells, creatures, champions - all must be PURGED (not simply consumed). I have no idea how someone would ever manage to do this in a normal run of the game - but thankfully we don't have to. We'll be using a seeded run that was posted by rjr619 on Steam instead:

From the main menu, select:

- Challenges
- Community Challenges - Play
- In the Join Challenge section type in: IrishOccurPraise

Pick Up Thorn Fruit initially and play Stings throughout the run. There is an artifact shop (Merchant of Trinkets) about half way through has both the sting relics in it to pump up their damage. You will be forced to purge one card after each fight, but along the way hit a few Unstable Vortex to remove additional cards and pay to have some removed if necessary. Make sure you go into the final battle with absolutely no cards in your deck and your pumped up free Stings will be enough to win!

NOTE: If you have any trouble with the above seed, there was a time it no longer worked. During that time a few others were found that could manage this achievement, and I'm leaving them here just in case someone runs into an issue and wants a few others to try:

- UPDATE: the latest DLC seems to have changed these seeds. BIG shout out to Aurelain for finding a new one that works! MatchingRetainPlaza
- UPDATE part B: MagicRealism also found one that works (name: InvolvedSmartQueries) and included some specific steps in the comments below.

As I see a lot of comments from people having trouble with set seeds, I wanted to find a solution that didn't rely of seeds from other people. With that, I'm adding a new guide to say that...
This can totally be done on a random new standard run (with mutators of course)
I won't lie, there is a fair bit of RNG in this run regarding the artifacts you get, but if you play smart, collect a lot of gold and pick well in the merchants you can get everything you need. Also note you can retry battles if they go awry by quitting to main menu and then continuing the run.

I saw someone saying somelike like "I don't know how anyone can do this without a seed." so I took it as a challenge. I got the achievement within three attempts, and the first one only failed because my final unit died on the same turn as Seraph and the permadeath mutator didn't trigger, leaving me with one card... who knew?

Here is the set up I used for new runs
- Primary Clan - Awoken - Pick The Sentient for healing spells
- Allied Clan - Hellhorned - Pick Queen's impling cards
- Mutators - Hashtag Blessed, Permadeath, Fallen Champion
- Covenant 0

Overall goal
Restart the run until you get the Thornfruit from the initial artifact at circle 0. If you don't find it later on, the run falls apart. Thornfruit gives you Thorn spells every turn which can be powered up to do a lot of damage, and pierce armor.
Always use every Thorn spell so you draw more next turn (they can be used on an empty floor)
The fallen champion mutator takes care of removing your champion card, and permadeath helps you remove the Train Stewards and Imps by purging them when they die.
You want to recruit enough decent units to get yourself to the final Seraph boss, then have them all die by the time you have done enough damage to finish off Seraph with Thorn spells
Purge all your spells before the start of the final fight (use the vortexes or card removal service).
I picked +1 draw crystals, but the draw affect of the Thorn spells means this is not neccessary.

Getting the right Artifacts
As previously mentioned, restart until you get thornfruit at the start of the game (use the restart arrow in the pause menu for speed). I don't think turning down an artifact means that artifact is unavailable, but I restarted if there was a useful artifact next to the thornfruit in the first pick, just in case.

Hashtag Blessed mutator will give you free artifacts after every battle. Always take the artifact, even if it doesn't help the end goal. Taking it removes the artifact from the draw pool and makes the good ones more likely to appear.
The only artifact I would suggest you turn down is Volatile Guage, this will completely mess up your thorn spells.

You will have to finish the final boss with Thorn spell, so pick artifacts based on how much they help you powerup and fire off lots of Thorns each turn. You'll want to collect gold and aim for merchants of trinkets when they appear to have a pick of six artifacts (with re-roll), only buy the most essential artifacts. And only spend enough gold in the steel and magic shops to get you to the final fight. Also don't re-roll trinkets if you won't have enough money for them

Always pick these artifacts if available
Channelheart - Powers up Thorn spells +20dmg
Thorn Casing - Powers up Thorn spells +10dmg and makes them piercing (good if you get white Seraph)
Frozen Nostalgia - +15 magic power = increased spell damage

These are really useful
Winged Steel - draw 1 when you play three cards, can let you play an extra thorn each turn
Guild Marker - Especially early in the run, discount on merchant of trinkets is really useful.
Imp-cicle - Gives you imp cards that don't count towards your deck count at the end of the run (and combined with Queen's tail can let you draw more thorns)
Cursed Vines - Another free spell in your hand that doesn't affect your deck count. Can be good for getting weak enemies at the back or for shifting units.

These can be helpful Pick up if there is nothing better
Tempered Talisman - +3dmg to your thorns, it adds up.
Infused Mallet - Can remove the units that Seraph spawns which can block a thorn spell
Jackstrips - Low health units in the Seraph fight can be tactically ignored if you know they will die before they reach the Pyre
Anything that powers up the Pyre (might be up to the Pyre to finish Seraph) - Boon of the Blacksmith, Vapor Funnel, Pyrewall, Precious Plating, Heaven's Gold, Blood for Blood
Anything that messes with enemy units - Cleansing Water, Concussive Coals, Winged Indulgence.


Getting to Seraph
You will want to pick up Units where you can, Permadeath makes them easy to purge from your deck when appropriate. Pick whatever units you are comfortable with, they will need to be able to help you get through the wave phase of the Seraph fight. Just make sure that whatever units you have, they are all dead before Seraph dies (I learnt the hard way that Seraph dying to spikes at the same time he kills your last unit will ruin the achievement attempt as permadeath doesn't trigger in this case). Don't be affraid to duplicate a strong unit
You'll mostly want to avoid picking up spells unless you are confident you can purge them before the final fight. I tried to rely on picking up Unit cards that worked well with the healing starter cards.
You can power up your spells and units, just don't spend too much gold on them, your gold is primarily for artifacts and card removal
Don't let your train stewards all die until you have good units to replace them.
Take trials if you can handle them, especially if an artifact is on offer. Spell shielded enemies trial is free real estate if your units are strong enough on their own to clear the round. So is armored units trial if you have the armor piercing thorns

Recommended units
Thorned Hollow, Awoken Hollow - The Restore spell will make these guys stronger the more you use it on them. (there are also healing/spikes artifacts that can make them really strong)
Vinemother - More thorn spells
Demon units depending on the artifacts/tactics you are going for - With the healing cards being likely your only spells, the high HP demons might be more useful. Demons are also more likely to be able to stand up to the waves in the final fight without healing spells

Final set up before the Seraph fight
Make sure you remove all spells from your deck, you should have only non-champion units in your deck.
Buy whatever remaining useful artifacts you can.
Any leftover gold, spend on your units if you have access to the merchant of steel.

Final Seraph Fight
Restart the fight as many times as you need to get your tactics right, don't let Seraph die with cards in your deck or alive friendly units, or let your pyre die early. Once any of these happen, you can't restart.
Don't sacrifice your units right away, use them to help you clear the non-boss units
Try not to have units on the top floor of the train unless you know they will die to non-boss units
If you have a friendly unit on the top floor by the time Seraph enters his combat phase, carefully measure how much damage you do to Seraph so that he can kill the unit and have low enough HP that the Pyre can kill him.
Try to clear out lower floors of enemies to let you hit Seraph with Thorn spells on subsequent turns before his combat phase.
Always use every Thorn spell so you draw more next turn
Don't do so much damage to Seraph that your units kill him before they die, if this is going to happen, quit to main menu and continue the run, try the fight again but put your units in more dangerous spots or use less spells on Seraph himself.
As long as the Pyre dooesn't die, it's OK to let the Pyre kill enemies


By the final phase, I had a couple units left, and Seraph had close to full hp. My thorns were doing i think 58 dmg each and I was drawing a full hand of them every turn. He killed the last of my units, removing them from my deck and I killed him with throrns on the top floor.


Hope this helps. Seeds seem to change over time and are different for people with and without DLC so my hope is this is a method that will work regardless of how seeds change.
That said, I shared my run seed, I got real lucky with artifacts, so if you want to try my seed, enter this code:
InboxRecoveryEditions
The +15 magic power artifact was in a concealed cavern. I picked it up before the Talos fight so pick the cavern path for this item.
Update - I wanted to test my method again, so tried once more, got it on my second attempt after bad luck on artifact draws first time.
The seed code is YearlyRemedyAnnual - This one the good Thorn artifacts don't appear until the merchant of trinkets about half way through, so make sure you get good units to carry you that far. On this run I had to seriously slow down my thorn spells to make sure Seraph survived long enough to kill my units.

Feel free to comment any tweaks or different tactics you find. There are a few ways to get this. Different methods might work better for different players. My first attempt that was messed up by the last unit death was done with Melting Remnant allied clan and the Dreg starter cards

I did this on Steam (which doesn't make a difference I'm pretty sure), but in case anybody wants another method or tips I'd agree with most of what Fluke939 said on the achievement, but a few modifications.

1. I think Imp-cicle is also an acceptable potential starting item instead of just Thornfruit. If you play it right, you can usually get some massive imps that win you the rounds by playing it right. If you do this, try to go for the Consumer of Crowns (kill him on the last boss) at a banner/unit draft reward, as it makes most fights a breeze when you plop him down.
2. I suggest going for +1 mana crystals not +1 draw crystals, some enemies will have scourges that you need to purge using mana and it helps you play any minions or other spells. Meanwhile +1 draw doesn't help at all as if you get thornfruit you will be drawing your whole hand or the max of 10 every turn regardless.
3. You can easily have a spell or two before the crucible and then pick the Unstable Vertex path to remove them or if you haven't purged many spells then through the shop.

My seed can be accessed by using code "DeservePlateNormal". For reference, upon arriving at the Crucible I had an Imp-in-a-Box (which I then purged obviously), 2 Boneshines (purgable X-cost spells that can be used to heal your core, just in case), and a quick, largestone, multistrike Consumer Crowns along with Thornfruit, Imp-cicle, Improved Firebox (allows Consumer of Crowns to be played first turn), and the +20 power and +10/piercing for Sting spell artifacts. There's even a option to get the demon multistrike artifact but I was afraid this would my monster unkillable.