We already know Rumari cares about her brother very much, but she's not the only one. Sakuro often states being Ureksa's friend. Sakuro was born in a distant land, but it is not revealed exactly where. He and his parents were ill when they were attacked by robbers and almost killed. Sakuro doesn't reveal much about the events, other than that it was raining, because he was too ill to remember in detail. Shintetsu helped him and in his own words, made him who he is. Sakuro decided to travel with Shintetsu later after this. He mentions that Shintetsu traveled to see what his swords could do. Sakuro wants to travel for that reason too, believing there are also things that only he can do. He wants to travel to his home town and one day return to Wystern. However, he won't leave Wystern until the situation with Parista is resolved.

When Lubert bad mouths Ureksa and Cleru or Pratty, depending on who you play as, stands up for him, Sakuro thanks him or her. We see Sakuro taking a somewhat patient attitude for most of the game. He's generally calm and accepting of the fact that the situation must be taken slowly and a panic must be avoided while they find a solution. When Sakuro thinks Ureksa has died, that's too much to take with the same patience as before. From that event on, Sakuro takes a more direct approach to the Parista problem. At that point, the Craftknights, especially Pratty or Cleru, are more aware of the situation.

When it is revealed that Ureksa was kept alive by Parista to be further used, Sakuro is happy to have him back. Fortunately, Ureksa is freed from Parista's control and we see Sakuro smile as he helps his friend get to safety to have his wounds treated. Sakuro's gratitude for the relatively safe return of his friend seemingly from the dead is clear. He also gave me the impression of playing a bit of a big brother role, perhaps inspired by how Shintetsu helped him in the past.

Tyram, Rumari's boyfriend, certainly earned his title of Tyram the calm. Ureksa was convinced that Tyram had accepted Rumari's illness, though he was secretly researching a cure. I think he didn't tell Ureksa right away so as to not make him impatient or get his hopes up too soon, but ultimately the lack of communication was bad. I elaborated on that in the section about Ureksa's story.

Tyram also allows Ureksa to capture him and hold him prisoner, which leaves Rumari to worry. Tyram wants to reason with Ureksa, but ever the calm, he mostly sits around locked up until Cleru or Pratty and his or her friends get involved and free him. Then he blurts everything out on the roof and Ureksa goes over the edge, literally. I know Tyram had good intentions but bad timing.

This well intended inaction brings me to my next point. During Cleru or Pratty's meetings with Kouren in Wystern, she speaks of what makes a hero and how people define it differently. She speaks of "the one who turned to darkness" and throws a variety of hints about Ureksa that the player may or may not catch at that point, but are clear upon replaying the game. She knows; Kouren might not know all that's going on, she might not know how far Ureksa would go, but she knows something bad is going on. Cue the lack of communication.

I get the impression that the other Craftlords, especially Tyram, Sakuro and Kouren, are trying to protect Ureksa. They're patient with him and they don't show indications of having confronted him off camera, everything points to conclude they didn't. It stands to reason that they may not know the extent of what Ureksa is doing, but it's obvious they have big suspicions, they know enough to take action, but they don't. This is different from catching a criminal in the act, they want Ureksa to take the right path. Thus Cleru or Pratty is set up to be involved in hopes that will make Ureksa realize the error of his ways. The young Craftknight is sent to run some errands with him.

From what I can interpret it's typical denial. Our dear friend, whom we certainly don't want to imagine would sell us out to the enemy, is doing some bad things, but it can't be so bad, it has to be a misunderstanding. What was going on hurt Ureksa's friends, they wanted him to fix it and worried about the repercussions of a more direct confrontation. Unfortunately it was inevitable and by then, all the pressure had piled up too high and took Ureksa down.