Slay The Spire

I found it much easier to play as the Ironclad, keep the starting relic and build a basic Block / Body Slam deck. I was trying for ages to get lucky losing the starting relic and hoping for something better but I got it on my first try doing it like this.

This type of deck revolves around building Block and using Body Slam to deal damage equal to your Block and is a really easy deck to build.

Useful cards are:
- Body Slam+ (Cost 0, deal damage equal to Block)
- Barricade+ (Block isn't removed)
- Entrench+ (Double your Block)
- Juggernaut+ (Deal damage when you add Block)
- Rage+ (Gain Block when you attack)
- Shrug It Off (Gain Block and draw 1)
- Iron Wave (Deal damage and gain Block, amazing with Rage+Juggernaut)


Here's a screenshot of my run and a clip of me beating the final boss:

I waited until I had gotten all characters to A20 before attempting this. After having learned all of characters pretty in depth it became painfully obvious to me that Watcher is significantly stronger than the other 3 characters (although prior to watcher's existence I'd agree that Ironclad was the best for this achievement).

To put this into perspective a little bit, here's how many runs it took me to get each character to A20:

Ironclad: 54 runs
Silent: 66 runs
Defect: 87 runs
Watcher: 27 runs!

So with knowing this I figured Watcher was definitely the best character to get this achievement, so I went for it and got it on the first try (albeit with some luck).

Some things to take note of when going for this achievement:

Watcher is a great candidate for Boss Relic swap from Neow. You're hoping to get any energy relic, as you're trading an extra energy on 1 turn per combat for an extra energy for every turn per combat. On my run I got velvet choker which isn't necessarily the best for watcher, but I made it work.

You will want to try to path out as many campfires as possible so you can upgrade cards early as Watcher destroys act 1 with 4 energy. I did not have to heal once in act 1. One thing to note is I got offered an early Lesson Learned, which is great to get early as it is easy to draw out some fights and get even more upgrades. I'd recommend upgrading Eruption so it becomes 1 cost making it easier to get in big damage turns or to get extra energy from using it while in calm.

My general thought process when playing watcher is to get a lot of cards that help do a lot of damage in a few turns but also have quite a few cards that let you exit wrath when you need to.

Some Watcher cards that will get you out of wrath are:
Vigilance (starter card)
Empty Body
Empty Fist
Empty Mind
Fear No Evil
Inner Peace
Meditate (premium option, especially upgraded)
Tranquility

Some Watcher cards to look out for that when I see I almost always take without question:
Wallop
Meditate
Talk to the Hand
Third Eye
Cut Through Fate
Tantrum
Spirit Shield
Scrawl
Blasphemy

Some Watcher cards that I'll take often depending on how the current deck is looking and what I'm missing to make the deck stronger:
Bowling Bash
Crush Joints
Follow-Up
Halt
Protect
Sash Whip
Battle Hymn
Carve Reality
Conclude
Deceive Reality
Perseverance
Reach Heaven
Sands of Time
Wave of the Hand
Wheel Kick
Windmill Strike
Worship
Deva Form
Devotion
Lesson Learned
Omniscience
Ragnarok
Vault
Wish

I realize I've listed a lot of cards here but the intent is to help people who are not as versed in Watcher identify cards that can help take their decks to the next level.

Even with the luck that I had on my attempt at this achievement I still made plenty of mistakes that almost cost me the run which will show you that there is quite some wiggle room to getting a winning run. For instance taking Alpha almost cost me my run as it clogged my starting hand and I rarely got to play Omega so it just gave me dead draws. Master Reality and Battle Hymn are usually a good combo but my deck was too big to utilize them more often than not so again, wasted draws. Another big problem I had was accidentally winning a second Eruption from the matching card event as it never got upgraded and I already had several cards to get into wrath. My deck overall would have been much stronger if I had kept it closer to 30 cards instead and also would have benefited from more strike removes.

All in all this achievement is very doable with Watcher with Boss Relic swap, just expect it to likely take several attempts for the stars to align. Last thing to note is to not accidentally take relics from chests/events/elites as its very easy to autopilot and take them by accident.

I'll post a screenshot below of my run and if anyone has any questions about the run or even for just general watcher advice, feel free to leave a comment.

There are three guides for three separate characters, but since I beat the game with 1 relic with Defect, I thought I should add my quick summary here. Defect is my favorite character, and after trying many times with Ironclad (which seems to be the default for many of these tougher achievements), I got this first try with Defect.

In my opinion, dropping the starting relic for a +1 energy boss relic at the start would probably be easier for this build, but I didn't have the option so I went with +7 hp and still got the achievement. Generally, as the other guides suggest, do your single relic run without ascension, and avoid all elite battles. For cards you want to stack up on Block and Power cards. The general strategy is to turtle with block, while building up your offense with powers through Creative AI. Here are the cards to look out for:

Powers
Creative AI This is a must! Upgrade if possible so you can also add some block if necessary during a turn.
Electrodynamics
Machine Learning
Capacitor
Defragment
Heatsinks
Loop
Self Repair
Storm

Skills
Charge Battery Very helpful for building up defense and extra mana for powers the following turn.
Auto Shields Only one is needed, but it gives a ton of block for the cost.
Boot Sequence - also good.
Force Field - Grab as many as you can, these will start costing 0 in no time
Genetic Algorithm
Glacier
White Noise
Cool Headed
Leap
Stack - later in the game
TURBO - I found handy for building up defense and power, but recognize its drawbacks on later turns.
Double Energy - has utility when your hand gets big, and especially when it is upgraded and paired with other mana generation.
Amplify - will help to snowball powers
Seek - I found this handy to find just the right card. I often sought Apotheosis and Creative AI, if I didn't start my combat with it in the first turn.
Apotheosis - I found this really handy for decreasing costs and increasing block values during combat.

Attacks - I added very few attacks, but a couple that helped were:
Melter - this was nice for a few opponents that stacked up on block.
Sweeping Beam - card draw and AOE damage
Some minor card draw might help to round out your deck.

As you're working through the map, again avoid elites, but try to get to campfires for rest or smithing and get to shops if you have a lot of extra gold. If you're removing cards, start with removing strikes (or curses if you have them) and then defends. I may have gotten lucky on the Act 3 boss as it was Time Eater - I didn't need to worry about card limits so much since my accumulated powers were doing the work for me, not my attacks. Hopefully that helps, but leave any questions for me in the comments!