In a certain way, he’s actually a little like Gaara when he first debuted. Now, this isn’t an insult or anything of the sort. Because there are quite differences as well. It’s clear that he does love his family (adoptive family, but in my point of view, blood isn’t important), and he has a LOT of respect for Shikadai. He does show compassion and empathy and does respect others, and he doesn’t push Yodo and Araya around. So he’s far from a bad person. But here are couple of ways that he is a bit like Villain!Gaara:
1. He really can’t see Boruto as a worthy ninja. He actually seem aggravated with him at best, like Gaara was with Naruto. Though while Naruto wasn’t a prodigy (at first) and worked hard to get where he’s at, Boruto IS something of a prodigy and STILL cheated during the Chunin exams. Because of that, it’s little wonder why Shinki has this view of him.
2. Shinki also appears rather humorless, like Gaara was. Though while we know Gaara wasn’t a ball of sunshine, as his character developed, he certainly wasn’t above a couple of snarky moments, as seen with the 3rd Tsuchikage and the 2nd Mizukage. It’s likely that Shinki also had trauma in his life, but what he went through has yet to be seen.
3. Apparently, he has a hell of a death glare. While it didn’t scare Kankuro, he didn’t like how Shinki looked at him. He probably learned that from Gaara. Maybe he, Araya, and Yodo were caught raiding sweets one too many times…
I also get the idea that he might be trying a bit too hard to emulate Gaara at times, which would make him a really nice foil to Boruto, who wants to be his own person rather than being compared to Naruto all the time.
But that’s just me. Let me know what you guys think. :)