So you've come to the point where the lovely red head has joined your group, and you're wondering how to make the best of her quickly! Well, this short guide will give you a few hints and tips about what works good. There are many possible strategies, so feel free to add your own tips to this guide if you've got something different working for you!

Silo Pipes
Your economy building is very peculiar: it has infinite range and will automatically connect to the nearest ore to start automatically mining. The pipes will start producing weapons depending on the color of the ore being mined, and these weapons can be grabbed by your soldiers.

Knight's Keep
Your main offensive building will be producing little soldiers that do nothing, until one of your pipes has produced a weapon! They'll slowly walk to grab a gun and then they'll be ready to hunt! You can move the soldiers to any location, so the barracks themselves don't need to be on the frontline, as they will produce more soldiers should the original die. The soldiers can be improved into squads, or solo super soldiers, and there's a lot you can do with them!

The Walls
Fie has a very unique wall. It is rather cheap, and has a lot of upgrade paths, but the gist is that each wall touching another wall will share most of its upgrades with the rest of the lot. Improved health and defense will propagate like this, so you can end up with very strong walls. There are self exploding options, an offensive wall, others that can host your soldiers, so options are aplenty if you have the space to build a big block.

Rest Stops
Last but not least, Fie has a support building that grants bonuses to nearby units. Place one near your different squads to grant them extra range, extra attack speed, health regeneration and a few others useful buffs.

Due to how ores work in the game, there are 7 colors of guns that you can produce for your soldiers with your Silo Pipes. Each has its functions and uses, and here's a short description of each:

Red: machine gun that shoots a few bullets. Very good against enemies with armor.
Blue: shotgun with a burst of damage. Great defensive option in walls.
Yellow: sniper with long range. Great to one shot smaller units.
Orange: rifle with piercing. Good placement can ensure that many targets are hit.
Green: pistol. Fastest unit and very good if you need to move a lot.
Purple: grenade with area of effect. Great at clearing piles of units in front of walls.
White: ex rifle. The ultimate gun and only available on one map, as far as I know. Your super soldiers will be good in all situations, with fast medium range shots that hit twice.

That's not all though. There is an upgrade on the barracks called Trailblazers that will provide your soldiers with extra abilities. It is available both on the squad and solo soldier paths, although will prevent your squads from having more than 2 members. The unlocked new abilities are:

Red: faster shooting speed
Blue: adds a short stun to attacks
Yellow: provides extra range and attack power
Orange: damage dealt will take a % of the total health of the target
Green: makes your units faster and untargetable.
Purple: enemies killed by your soldiers will drop a grenade
White: gain additional damage on each enemy killed

• Your first Knight's Keep costs 60 red, and so you should rush to an ore containing red ASAP otherwise you will be defenseless, especially if playing solo.
  
• You are a strong economy characters because you can mine those hard to reach high level ores. Build smartly around the map, but also make use of the Reroute ability on your Silo Pipes to build safely and mine from afar an ore of your choosing.
  
• Your Silo Pipes will produce guns, but those guns are only available to your soldiers if they can reach them. That means leaving an empty space next to your Silo Pipes. As you fill the map with Silo Pipes, it can become beneficial to make dedicated Silo Pipes close to your Knights keeps that have Arsenal (you choose which color of weapon they produce) or that other upgrade that gives a speed boost to your soldiers on pickup. This will give you great control over gun distribution and allow better replenishment of your frontlines should soldiers start getting hurt.
  
• You need space, a lot of it. Your Knight Keeps take a spot for the building and another for the soldiers to stand on. Your Silo Pipes require at least one open side (on the same level) if you want the weapons to be accessible. Plan ahead, and let your teammates know.
  
• On the plus side, soldiers can stand on unbuildable tiles, making Fie a great pick on some maps.
  
• It can be beneficial for you to build your Knight Keeps farther back, next to the crystal even, so that they walk to weapons on the way to their spot.
  
• Your walls aren't the best, but the ones that fall will make the next generation stronger as the surviving walls keep getting properties propagated in them.
  
• Keep Rest Stops for later. You should focus on economy first, and then once you have enough yellow, start buffing your units.Basic tips
  
• Your first Knight's Keep costs 60 red, and so you should rush to an ore containing red ASAP otherwise you will be defenseless, especially if playing solo.
  
• You are a strong economy characters because you can mine those hard to reach high level ores. Build smartly around the map, but also make use of the Reroute ability on your Silo Pipes to build safely and mine from afar an ore of your choosing.
  
• Your Silo Pipes will produce guns, but those guns are only available to your soldiers if they can reach them. That means leaving an empty space next to your Silo Pipes. As you fill the map with Silo Pipes, it can become beneficial to make dedicated Silo Pipes close to your Knights keeps that have Arsenal (you choose which color of weapon they produce) or that other upgrade that gives a speed boost to your soldiers on pickup. This will give you great control over gun distribution and allow better replenishment of your frontlines should soldiers start getting hurt.
  
• You need space, a lot of it. Your Knight Keeps take a spot for the building and another for the soldiers to stand on. Your Silo Pipes require at least one open side (on the same level) if you want the weapons to be accessible. Plan ahead, and let your teammates know.
  
• On the plus side, soldiers can stand on unbuildable tiles, making Fie a great pick on some maps.
  
• It can be beneficial for you to build your Knight Keeps farther back, next to the crystal even, so that they walk to weapons on the way to their spot.
  
• Your walls aren't the best, but the ones that fall will make the next generation stronger as the surviving walls keep getting properties propagated in them.
  
• Keep Rest Stops for later. You should focus on economy first, and then once you have enough yellow, start buffing your units.

I was playing mostly in teams of 3, and we usually used other characters walls, but Fie has three tools that can be useful:

• Exploding walls can be great to prevent those super fast fractured enemies.
  
• True Walls, although expensive, reset an enemy damaging them, meaning they return to their spawn point and must recross the map. I believe this works only once, but it can be a game changer against beefier units. Note that bosses will respawn but then teleport back to the wall, only gaining you a few seconds instead of a full map crossing.
  
• You can build walls that can cover your soldiers but this reduces their attack damage.

There isn't really a better solution between bigger squads, trailblazers and solo knights. I like scattering solo yellow snipers here and there in the map. To beat bosses, trailblazer orange squads do wonders. Against waves, large squads with varied weapons can clear everything. I would suggest to do a bit of everything, and to try to cover known weaknesses in your team if playing multiplayer. Try all the guns, with their Trailblazer alternatives, and figure out the combinations that match your team best.

Like almost all other vessels, you will need a lot of yellow ore to get any form of economy going. Your Silo Pipes cost quite a bit of yellow ore if you want to keep them in the economy line: the first stage of the pipes is 35 yellow ores, and their only level 1 upgrade costs 30. This doubles the silo's efficiency and should be purchased before placing more silos if possible. Their Old Pipes upgrades will let them connect to a second ore vein, which can be very useful, but this upgrade costs an additional 225 yellow ores and is only found at level 4, which means you'll need to dish out more resources for level 3 before that.

Red is also a hot commodity. Your first squadron will cost 60 red, meaning you will need to start mining red really fast to have any offensive presence on the board. The second member of a squadron is actually cheaper than a new building, at 55 red ores, and that should be your option unless you need to cover vastly different areas with your first few soldiers. Most of the upgrades on that building will cost red ores in larger and larger quantities: 130 for the third squadron member, 300 for the fourth, 85 for Trailblazers, and so on.

Blue you will not need as much unless you are the one responsible for static walls. It is used in most upgrades of The Wall, and most upgrades that feel defensive on other buildings. Otherwise its second largest use is on the Rest Stop in various quantities.

As such, the cardinals I recommend the most are: the Red Coin, the Blue Coin, the Yellow Coin and the Green Coin. Yes, you read me right, all the coins! The colors you need a lot of will come faster in the first few rounds, and the ones you need less, like Blue, you will be able to ignore longer.

• You can put units inside walls with one of the wall upgrades. Put blue shotguns with sword attack in there for retaliatory defenses!
  
• Onagers are an issue? Build a green Trailblazing squad and move them forward. They can't be targeted and can me moved very fast, letting you murder those siege atrocities faster.
  
• You are on that one map with Opal? Make two or three white riffle Trailblazing squads and place them high up near the enemy spawns. Rest for the remaining time as your squads solo the whole level. Build a few more squads at higher difficulties.
  
• Playing with someone fond of Beacons? It's time for purple grenades!
  
• Rest Stops can apply their buffs to walls and towers on one of their upgrade paths. This means that they can offer health regeneration to them as well. Not the fastest heal, but it can save your allies' buildings!
  
• If you survive well but the last boss wave is what's killing you, consider orange riffles with Trailblazers. Distribute a number of those duos all over the path of the boss and they will melt the boss' health. Even better: make a kill-room ambush with them right where it spawns! Collateral damage will be kept to a minimum!

I hope this short guide has been helpful in some ways! Fie has been my favorite character in the game and I'm still discovering some of her gimmicks. She's very versatile and will fit many teams too. If you have strategies, ideas, or comments, let me know and I can edit this guide!