Shinki was just revealed to be the persona of the new Shinju, that was introduced in Boruto: Two Blue Vortex chapter 13. After many debates and takes on who would be the persona of the Shinju, chapter 14 just confirmed that it was Shinki. He is the adopted son of Gaara, who could control Iron Sand and was an ally of Boruto.
Apparently, Shinki and Gaara were attacked by the claw grimes, which ultimately changed Shinki into a tree. This in turn created his Shinju named, Ryu by Jura. If the consuming pattern of the Shinju is true, then Ryu would most probably want to devour Gaara, as he is the most closest to him. This is the same with Hidari and Sarada, who are connected via Sasuke as being the closest one to each other.
This development changes everything, since Boruto has to ultimately defeat Ryu, in order to free Shinki. Not much has been seen from this new Shinju, but we can assume that it is as powerful as the others. Also considering the Shinju emulate their persona, he would most likely be able to use Shinki’s iron sand in battle. Thanks for reading the article, and comment down below on what you think about this development.