Advance Wars Wiki
Appearances Advance Wars: Days of Ruin
Specialty Everything
Affiliation IDS
CO power None
CO Zone 3
Hits Unrestricted experiments
Misses Ethics
“The head of the private military contract IDS. He seeks a world where he is free to carry out his terrible experiments.


Advance Wars: Days of Ruin CO Description

Caulder (Berith and Stolos in the Japanese and European games respectively) is the main villain of Advance Wars: Days of Ruin. He is a CO and head of the private military contractor IDS. He seeks a world where he is free to carry out his horrific biological and psychological experiments.


He is first seen in Fear Experiment, where he and his daughter Penny destroy one of the few remaining food sources and where they unleash the War Tank on the 12th Battalion, just to see how they react. Later on, he supplies The Beast with the weapons which he needs to defeat the 12th Battalion. After The Beast fails Caulder kills him.

Afterward, he is seen supplying weapons to the Lazurian Army Supreme Commander General Forsythe. He offers to let Forsythe use his terrible weapons, but the General turns him down.

Admiral Greyfield, leader of the NRA, is not so reluctant though. He has Caulder use a Weapon of Mass Destruction on a ruined city in order to kill Captain Brenner. Afterward, he and Tabitha are seen using an IDS prototype weapon, The Talon Gun, to attack the 12th Battalion and Lazurian Army.

The heroes meet him in the aftermath of Waylon Flies Again. It seems that he was in a ruined building, observing the whole battle. He informs them that Greyfield is almost ready to use his "Masterpiece".

One of the civilians, Dr. Morris, sheds some light on who Caulder is; a scientist whose only interest is to carry out unethical experiments. Lt. Lin infroms them that Caulder is the head of IDS, or Intelligent Defence Systems. He was making a huge profit from the Lazuria/Rubinelle war by selling weapons to both sides. Isabella then says what this "Masterpiece" is: The Caulder Missile. These were sold to both side of the conflict, and all of them were set to launch simultaneously. Frightened by the implications of this, the 12th Battalion sets out to stop the launch.

Throughout the game, there are references to a virus the Creeping Derengea (known as the Creeper to the 12th Battalion and The Green Thumb to the NRA). The virus is tearing through the NRA, and Greyfield orders Caulder to find a cure, or else. Caulder says yes, he has a cure, but there's a more pressing matter; The Caulder Missile System was damaged by the meteor strikes, and that there are a number of locking mechanisms that must be bypassed. Fortunately, the 12th Battalion stops these weapons from being launched.

Once Greyfield dies, Caulder decides that the 12th Battalion might "prove to be worthy specimens for further research." He gives his children Cyrus, Penny, and Tabitha a new "toy"- the giant bomber The Great Owl. He will call off his plane though, he says, if they turn Isabella over to him. They refuse, and Caulder begins the attack. The 12th Battalion barely manages to defeat him.

After he first unveiled the monster plane, he reveals who Isabella is: one of his cloned children. This changes the civilian attitude toward her. They decide to ostracize her. Not used to this kind of behavior, Isabella is so shocked and hurt she goes and surrenders to Caulder, who has her placed on The Great Owl.

This act prompts Will to go and rescue her. He does, but Caulder orders Penny to crash the plane and kill all who are on board. Isabella convinces her otherwise, and after Tabitha's stunning defeat, he calls his children "abject, useless failures!".


Caulder kills the civilian mayor by tricking him into taking poison that he falsely claims is the cure to the Creeping Derengea and then forces Cyrus to take a poison, that apparently gives a very slow and rather painful death (according to Caulder), after he defected to the 12th Battalion. Will finds Cyrus, who is on the verge of death, and is informed that Caulder has retreated to The Nest, his Headquarters. Inside the Nest is the cure for the Creeper virus. Cyrus dies afterwards.

The heroes pursue Caulder to The Nest, his crowning achievement and the central research facility for Intelligent Defence Systems. The Nest is similar to the Black Hole's Factories, only it's far larger, and is able to fight back. It's been armed with five powerful laser cannons, two of which rotate, and two powerful mortar launchers. It can also build any Land and Air Unit (around day 6, he builds a Seaplane Unit).

During the course of the fight, he tells a little story. He says that, in his youth, cloning technology had advanced by leaps and bounds, but that there was some ethical resistance to the idea. He rejected such concerns, and decided to clone himself multiple times, and to use the clones for organ transplants and for horrible experiments. Eventually though, the clones began to resent being used in such a way. They fought back. After a brief, bloody war, only one clone survived- and he is that survivor! He is a clone, and he killed his creator.

Eventually, The Nest is destroyed, and Caulder perishes along with it.

CO Abilities


Caulder's Theme

Puppet Master

CO Zone

+50% ATK and DEF to CO unit and any units within 3 spaces of it.

All units in zone heal 5 points at start of day, healing costs funds.

CO Power



As Caulder

  • There are no maps where you play as Caulder.

Against Caulder

  • Mission 26: Sunrise (as Will): You must beat Caulder as fast and as aggressive as possible while being cautious due to the Nest's attacks. Take out the left cannon with your left troops, moving carefully. Then take out the right cannon with your bomber. Then gun for the 3 middle cannons. If you don't beat this level as fast as possible, Caulder's overpowered CO Unit with units near him will massively crush the masses to where it would be nearly impossible to attack and gun the middle cannons.
  • Trial 31: Comb Map (as Brenner): It is a 4-way battle between you, Greyfield, Forsythe, and Caulder. First, try to capture the 2 seaports near your location. Do not worry much about Forsythe trying to capture your base because he will be busy against Caulder for the majority of the match and Forsythe will struggle against Caulder due to CO boarding and Zone. Take out Greyfield first until you capture his base. Once Greyfield is gone, then aggressively approach Caulder to capture his base; his boarded CO will still be busy against Forsythe. Once Caulder is gone, finish off a weakened Forsythe (if not defeated).
  • Trial 33: Missile (as Brenner, pre-deployed): Ignore capturing buildings and ignore boarding CO via HQ because you will not have time do any of those. Prioritize on the missile silos while going on the offense. You should be able to hit the right silo on Turn 2 and the left silos on Turn 4. Caulder's AI will not get the chance to board a CO on a unit and the match should end in 5-6 turns.



Caulder is considered unbalanced in the game. In other words, he is disallowed in competitive play under all circumstances due to how powerful his Supreme Boost is.

Playing as Caulder

  • Wi-Fi: Caulder is banned.
  • Playing as him: Caulder's powerful abilities will allow you to practically dominate the map, using his CO Unit to rule and the entire CO zone can be used to vapourise anything in your path.
  • 1-on-1: For a survival guide, see below.
  • 3-Way or 4-Way: Caulder's strengths means it is ill-advised for him being paired in a team. Consider having a 3-team against him or a free-for-all.

Surviving Caulder:

Though it is very slim to beat Caulder, here are some ways to survive or possibly win:

  • Against the CPU, you may actually beat Caulder before he gets a chance to load a CO into a unit.
  • Play the indirect game. Using direct units is asking to lose because you'll take a ton of damage, even on veteran status and your own CO Zone.
  • At any time you damage Caulder's units, you better hope you kill those units in particular. Otherwise, a 5 HP heal in the beginning of his turn means you are going to get slaughtered next turn. Do not attempt the repair game (i.e. scratch his units so that he spends money on repairs) because chances are, the next turn would mean all your units in that area are dead.
  • Priortise the CO unit the moment it happens. The CO's power should not be left unchecked for long periods of time will be a death sentence for any unit foolish enough to get targeted by one of the CO's 'boosted' own.
  • Choke points can really help you out here. This will only slow down Caulder, but at this rate, you have only one shot to kill Caulder at this position. Otherwise, if he breaks your choke point defense, you are done.
  • An area filled with hiding spots (Fog of War only) works wonders, but beware of units that can simply pass through areas and show visibility on where your units are in addition to flare usage.
  • Against CPU units only: If the CO Unit is near a factory you own and his CO Unit is alone, this is your chance to trap the CO Unit with nothing but infantry. The CPU will not self-delete units, so this gives you a chance to trap the unit with Infantry. You'll be losing 1500G each time, BUT he won't go anywhere. Just make sure that no other unit is coming to rescue him. This trick will not work effectively against the sea because Gunboats are a bit costly and most maps may not have many Seaports to spam.


In order to unlock Caulder as a playable commander, the player must complete Mission 26: "Sunrise".


  • Caulder's European name, Stolos, is based on a demon of the same name, which is often depicted as an owl and is associated with herbalism. His Japanese name Berith is also that of a demon associated with alchemy.
  • He was removed from multiplayer in the US version before the game even came out, thus making him banned from competitive gameplay.
  • He is the one of the only 2 COs who does not have a CO Power, alongside with Forsythe. This is due to the fact that his CO ability is extremely impressive already (in comparison to the other COs' abilities),
  • He is the only CO in any Advance Wars game that heals 5 HP, alongside with Andy.
  • He is the only character to have died immediately as a result of the end of the battle.
  • He may have been inspired by Dr. Josef Mengele and Shiro Ishii, who were both notorious for war crimes in WWII. Josef Mengele was known for experiments involving human cloning attempts, while Shiro Ishii was the leader of Unit 731, which experimented in weapons testing including biological weapons. (Both of which Caulder is involved in in Days of Ruin).
    • Internally, he is referred to as "Mengel".


COs: IconCaulder.pngCaulder | IconPenny.pngPenny | IconTabitha.pngTabitha | Cyrus
Former COs: IconIsabella.pngIsabella