If I may, how long has that treasure been out?

If free pulls are once every 47/48 hours, there's 1 pull every 2 days. And since the super rares come at 700-1200, average, it can be assumed that the super would take 1400 days worth of free pulls, which is nearly 4 whole years, for the minimum 700. The only explanation to this would be if you had gotten him recently, and that you've been pulling for free every single day for about 4 years.

And if I recall correctly, ninja are ordered based off of level, then oldest, I can tell this is the case here as Naruto is first for 104, then more easy ninja. And seeing as how you have gotten Susasuke after Naruto, assuming that you've done just free pulls, that shouldn't make sense. As you don't have the 4th Raikage, ruling out the idea that you could've pulled him pre-sasuke. Thus, the only reason you could've gotten Kuramato before Susasuke would be if you didn't do any free pulls from 5 kage treasure, but please, what sensible person would stall on free pulls for no apparent reason?

Though, by free I assume that you mean you haven't spent anything. And that you've gathered free seals and have used them on here, right? Because I had to go ahead and rule out the idea of it being pure-free pulls.

Free seals as in seals obtained without spending any money.

Okay, hang on.

At the core, Dosu didn't want to fight Sasuke to get revenge for losing to him. He wanted to fight Sasuke as an act of defiance to Orochimaru. It was a response to realizing that Orochimaru saw him and his team as expendable and didn't truly care about their lives: in response, he decided that fighting, beating, and probably killing Sasuke would be a suitable final "screw you" to Orochimaru. It was to prove that he was, in his own words, "more than a mere puppet" (or, "not just Orochimaru's guinea pig" in a different translation). After that, he'd probably have gone rogue and detached himself from the Sound entirely, perhaps becoming a missing-nin or maybe even joining a different village.

But you are correct to some extent: when he confronts Gaara, he is clearly arrogant. When one steps back and compares this to the rest of Dosu's scenes, it's a pretty major Out-Of-Character Moment. He doesn't really display extremely blatant arrogance to the same level anywhere else in the series; in fact, he even warns Zaku after the latter is being arrogant and overconfident towards Sasuke. Instead he sways towards the more cautious and calculated side of things: he usually stops and an@lyzes the situation before acting.

So he should've been able to an@lyze that he was no match for Gaara. He already witnessed Gaara's power firsthand in his match with Lee. Keep in mind that at this point, he is aware that Lee would be able to beat him in a 1v1 even with his Ninjutsu, so why would Gaara, who's stronger than Lee, be any different?

What does this mean? Either he goes completely against character and doesn't an@lyze all of this, or he still goes through this an@lysis, but goes completely against character and (extremely) arrogantly decides that he could beat Gaara anyways. No matter how you look at it, he was bent by the plot to hype up Gaara, and one anomaly of a moment shouldn't get in the way of his status as a remarkable character.

Sorry for the rising waves of text. Of course, everyone has a few topics they're passionate about and Dosu is one of mine.

You know, I have to hand it to Tencent on their details. The Mystery Icon of Dosu's Resonating Echo Drill Mystery depicts the Melody Arm on his right hand, just as it is in the anime/manga. The scratches and details are all there too, albeit a few are a little off but that's ok since it's a tiny symbol.

If they put so much detail into him... what's the point of not releasing him? It just feels like wasted work.