Black march green april 2.png
We are the 13 month series, a weapon created by a pledge. Until the day when our true master appears and we become one, we promise to continue the destiny of blood and the curse... This is a cursed power. We will dance as we wait for that day.

—Chanting from Black March and Green April as they both ignite [1]

The Thirteen Month Series (13월 시리즈, 13 wol shirijeu; or "13 moon series") consists of an Arms Inventory and 12 sentient Ignition Weapons made by craftsmaster, Ashul Edwaru. They are bestowed by King Zahard to a formal Princess. In fact, the symbolic significance of the 13 Month Series is greater than any other weapon in the Tower.[2][3].


It is said that the Thirteen Month Series were made from materials provided by Zahard.[4] These weapons also vary in shape and function. For instance, one is a Needle and another is a Hook. The Golden November is the only S-rank among the Thirteen Month Series.

The 12 Ignition Weapons, when ignited by the user, release vast amounts of power. It is said that only a formal Princess is supposed to be able to ignite a 13 Month Series,[5] though Regulars such as Anak Zahard and Twenty-Fifth Baam have proven this to be untrue.

It is revealed that the Thirteen Month Series when combined together, would form half of the Key of the Tower that will unlock the floors beyond the 134th Floor. Apparently, the day Zahard announced that he would stop climbing the tower, he split the Key into two parts. He gave the first half of the Key to the blacksmith Ashul Edwaru. Ashul melted half of the Key and turned them into 13 weapons, which Zahard then made the princesses fight over.[6]

No matter how skilled the wielder is, they cannot force a 13 Month Series to ignite. Depending on the weapon's personality, it may refuse to listen to its owner. Baam managed to ignite Black March, however Yuri Zahard was unable to do the same despite being a formal Princess. When weapons of the 13 Month Series meet, they will resonate and their owners can feel it.[7]


According to Garam Zahard, The 13 Month Series were split up so that Zahard and his 12 companions could share this key.[8] It means that the 13 Months Series were first intended to be shared by King Zahard himself to his 12 most trusted companions because Zahard wanted 12 of them can help him to safeguard the key. The 12 of them are:


But since there are unexpected things happened between Zahard against his two companions, Arlen Grace and V later, who declared war against him, it seems that the sharing of the 13 Months Series was immediately cancelled by Zahard.

Many years after the great war between Zahard against Arlen Grace and V ended, Po Bidau Gustang, one of Zahard's companions, who had become family leader of one of the 10 Great Families, proposed Zahard to create a Zahard's Princesses system. This system will force the princesses to compete against each other and fight over the 13 Months Series, because it will become tokens that are proving them as "worthy" to become "Acknowledged Princesses" and that whoever princesses collect all 13 months can become Zahard's wife. But the reality is different. The first generation of Zahard's princesses were consumed by the evil magic of the 13 months and ended up hating and killing one another.[9]

It seems that Zahard agreed to this proposal because this would only help him to add another way of distraction to keep 13 months intact in the hand of Zahard Empire, so that it won't fall into the wrong hands and no ordinary people can have it. Because it was later revealed by Garam, that Zahard would use any necessary means to prevent any princesses from gathering all the 13 months.[8]

One of the necessary means that Garam mentioned about was also about the intervention of The Ghost of 13 Months. The Ghost apparently was a girl, she is the soul of a former princess' candidate who failed in the initial selection stage. The ghost resented the other princesses and made a deal with King Zahard to seep into the spirit of 13 months and torment the princesses. The ghost stole and took control over the bodies of those who ignited more than two of the 13 months and made them do her bidding. When the princesses are possessed, they went on "rampage" - Zahard will make their "rampage" as an excuse to execute and kill the princesses. There are over five princesses that were already sacrificed using this method. Zahard used this despicable trick to prevent any princesses from gathering all the 13 months. The ghost cannot possess the princess' body for a long time. The time limit for the ghost is only one week.[8]

Receiving a 13 Month Series

A Princess who has climbed the Tower and become a Ranker might be chosen to become a formal Princess who is also called a "chosen Princess".[10] Only a "chosen Princess" is eligible to receive a 13 Month Series,[10] as she has proven her ability by climbing the Tower.

Rules Binding a Princess

When a formal Princess accepts one of the Series, she must abide by a set of rules:

  1. She may not give or even lend a 13 Month Series to another person, otherwise they may be viable for execution by Zahard.[11]
  2. A Princess may own more than one weapon from the 13 Month Series, such as Yuri Zahard or Garam Zahard.
  3. A Princess can refuse a weapon from the 13 Month Series. Heice Zahard, upon becoming a Ranker, was presented with a 13 Month Series, but she turned it down for unknown reasons.

List of Weapons & Current Owners

The following consist of a list of the 13 Month Series, along with their previous and current owners. [12][13]

13 Months Series
Name Weapon Type Rank Owner
Silver January Unknown Unknown An Zahard
White February Unknown Unknown Unknown ownerEnne Zahard → None
Black March Needle B-rank Yuri ZahardTwenty-Fifth BaamAnak ZahardAndrossi ZahardYuri ZahardTwenty-Fifth Baam
Green April Hook B-rank Anak Zahard (original)Anak ZahardYuri Zahard
Yellow May Unknown Unknown Maschenny Zahard
Luminous June Sword Unknown Alphid Zahard
Indigo July Unknown Unknown Yuram ZahardGaram Zahard
Blue August Unknown Unknown Garam Zahard
Dark September Unknown Unknown Unknown
Red October Sword Unknown Hagipherione Zahard
Golden November Unknown S-rank Adori Zahard
Colourless DecemberSealed Unknown Unknown Enne ZahardSealed
Rainbow Undecimber Arms Inventory Unknown None

Notes and Trivia

  • The 13 Month Series all have their names engraved on them. The engraving is in Japanese, because their creator Ashul Edwaru uses a language based on Japanese.[14] SIU made it clear there is no significance behind this, as Chinese, Arabic and other languages are also used throughout this manhwa.[3]
  • The 13 Month Series is actually based on the lunar calendar where all months are based on moons.
  • According to Random Webtoon Fan, the Princess who collects them all would be granted the right to bear Zahard's child.[15] This has been revealed to be their official first purpose.[9]
  • According to Garam Zahard, the 13 Month Series was originally created by Zahard to split the Key of the Tower between himself and his 12 companions. Two would rebel once he decided to stop climbing while the other ten would stay loyal and become the heads of the 10 Great Families.[16]
  • In addition to bearing an individual sentient spirit, if any of Zahard's Princesses attempt to ignite more than one of the 13 Months Series at once, a malevolent ghost will possess them for no longer than a week, but use their bodies to go on a rampage; wreaking havoc and causing them to be branded insane and hunted down by the authorities. It was a deal that Zahard set up with the spirit of a failed Princess candidate from the first generation to prevent any Princess from collecting all 13 Month Series.
  • The 13 Month Series play a big role later on. Of course, it's a little early for them to make their appearance.[17]
  • The 13 Month Series are weapons that have special meanings, but not the most powerful weapons in the Tower. They are powerful, but they are a lot more special than powerful. After all, even wielding them is a previlage only a select few have.[18]
  • There are many other Ignition weapons apart from the 13 Month Series. Many Rankers use Ignition weapons as their main choice. And the 13 Month Series are good, but they are not the best.[19]
  • The color and month combinations hold references to other media such as The Hunt for Red October. Though this combination may be a coincidence.



Unclassified Items
Devices Section
Unclassified Device
Weapons Section
Basic Weapons
SpearHookSwordWandShinsu BombNeedle
13 Month Series
Unclassified Weapons
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