The Japanese term is Bannin Series (番人シリーズ). Portuguese localization uses “Conjunto do Guardião,” while English viewers will usually encounter Watchman Series.
What the Watchman Series actually is
The Watchman pieces are still Vital Instruments, but Episode 19 places them inside a much narrower group. The known objects belonged to the same person in the past and are now scattered among different users.
That makes the repeated emblem far more important than it first seemed. Before Zodyl explains the connection, the matching mark on Rudo's gloves and Amo's boots works as a visual clue. Afterward, it becomes evidence that apparently unrelated objects share a history.
The anime does not immediately hand over a complete catalogue or explain the original owner. Instead, it gives us enough information to reinterpret earlier scenes. That is why the reveal lands: the mystery was already visible long before it had a name.
Rudo's gloves are the piece that starts the mystery
Rudo received his gloves from Regto, the man who raised him on the Sphere. They eventually become central to the way Rudo draws value out of discarded objects, but Episode 19 adds a second question to their story: the gloves are part of the Watchman Series.

That distinction matters. Asking how Rudo's gloves work is a question about his fighting style. Asking how Regto obtained a Watchman Series object is a question about the history behind the item.
The reveal makes Regto's gift look very different in hindsight. He did not merely give Rudo a durable pair of gloves. He passed on an object tied to a rare set whose full origin the anime still has not explained.
Amo proves the matching emblem was not a coincidence
When the story reaches Penta, Amo's boots carry the same emblem as Rudo's gloves. Episode 11 deliberately calls attention to that connection before the series explains what it means.

This is the moment the mystery stops being something that could belong only to Rudo or Regto. The same mark appears on a different object, worn by a different person, in a completely different part of the Ground.
Episode 19 finally names the connection: Amo's boots are another Watchman Series piece. What looked like a repeated design becomes proof of a shared origin.
Zodyl's coat shows that the pieces are scattered
The third object directly identified by the anime is Zodyl's coat. That distribution is important. Rudo, Amo, and Zodyl are not members of one team and do not share the same goal, yet each is linked to an object from the same historical set.

Zodyl is also the character who actively tries to reproduce the mystery. In Episode 19, he explains that he attempted to create a new Watchman Series item and failed. The experiment did produce a different discovery: a way to create a giant trash beast with a Vital Instrument serving as its core.
That failure tells us a lot without requiring the anime to explain every technical rule. Whatever makes the Watchman Series special cannot simply be recreated through an obvious manufacturing process. Zodyl can study the pieces, but copying the original result is another matter.
Regto remains the unanswered link
Regto is not presented as a current wielder of one of the three Episode 19 pieces, but he cannot be removed from the puzzle because he gave Rudo the gloves. The anime's official character material states that connection directly.

That leaves one of the strongest unanswered questions of Season 1: where did Regto get such an unusual object, and how much did he know about it? The anime does not fully settle that question by Episode 24.
It is worth keeping fact and theory separate here. Regto having the gloves and passing them to Rudo is confirmed. The earlier history of that piece remains open within the anime-only spoiler limit.
The three Watchman Series pieces confirmed in the anime
Episode 19 lets us organize the confirmed information clearly:
- Rudo's gloves: given to him by Regto and central to his unusual ability to draw out the potential of discarded objects;
- Amo's boots: marked with the same emblem seen on Rudo's gloves;
- Zodyl's coat: another piece of the same series, held by the leader of the Raiders.
Belonging to the same series does not mean sharing the same ability. The connection Episode 19 confirms is historical origin, not identical powers.

That makes the Watchman Series feel less like a matching weapon set and more like scattered relics. Each object has followed a different path and can matter differently to its current user, while the old connection sits underneath all of them.
What Season 1 still leaves unresolved
The first season gives a firm answer to the basic question while keeping the larger mystery intact. We know the three identified items were once worn by one person, and we know Zodyl failed to manufacture another piece. What the anime still does not fully explain is who that former owner was, why the objects are so unusual, and how each piece ended up where it is now.
That is the best part of the reveal. It does not exist merely to put a new label on Rudo's gloves. It pulls Regto, Amo, and Zodyl into the same historical question even though their present roles are very different.
Is the Watchman Series the same thing as Vital Instruments?
No. Watchman Series pieces are Vital Instruments, but the Watchman Series is a specific group with a shared origin. Most Vital Instruments are not part of it.
How many Watchman Series pieces does the anime confirm?
Episode 19 directly identifies three: Rudo's gloves, Amo's boots, and Zodyl's coat. That does not mean the anime has revealed the full extent of the series.
Was Regto a Watchman Series wielder?
The anime confirms that Regto had Rudo's gloves before giving them to him. It does not fully explain Regto's earlier connection to the set by the end of Season 1.
Did Zodyl successfully create a new piece?
No. His attempt failed. The experiment did, however, lead him to discover how to create a giant trash beast with a Vital Instrument as its core.