Kurama's yin chakra and sensing it...
I know that there are a bunch of threads regarding the Shiki Fuujin and Kurama's sealed chakra, so I thought I'd clear some stuff up with manga pages and bring out something to discuss.
In regards to how Shiki Fuujin works, Kurama's yin chakra is definitely not sealed inside Minato at the moment.
If it is, Oro's arms and the two previous Hokage's should have been sealed inside Hiruzen too.
Plus, it has been stated that the sealed and the sealer will battle in the belly of the Shinigami for eternity, or in this case, till the seal is broken.
With this out of the way...
It's been shown that people are able to sense Kurama's chakra in one way or another.
Hell, it's a pretty hard chakra to miss.
My point is, Oro, who has shown particularly good sensing abilities and Sasuke who is actually able to see chakra and give colour to it in the process, haven't mentioned anything about a huge amount of chakra that they didn't account for whooshing out of the Shinigami's belly.
On one hand, I'm sure that Kishi hasn't forgotten about said yin chakra after mentioning it a bunch of times and I have a hunch that all this thing about Sasuke wanting to learn the truth and breaking the seal of Shiki Fuujin was also in order to set Kurama's absent chakra free.
But on the other hand, I don't see how those bosses (namely Oro and Sasuke) who were present at the time would fail to sense such a monstrous amount of chakra.
I honestly hope this is just Kishi's way of creating suspension, otherwise I'll be pretty disappointed if the yin chakra isn't mentioned again.
PS: I've translated the parts regarding the breaking of the seal in 618.
The following is from the RAW.
その巻物に書かれている ことをする の に はまず 死 神 が 必 要なのよ
それは木の 葉のハアずれのうずまき一族の 能 面堂にある そしてまずは屍鬼 封尽の 死 神を己に憑 依させ導きだす
死 神の 腹を 裂 けば 封 印が 解 ける ただ 私 が 人柱に なる 必 要 はあるけどね これで 死 神の 腹の中にあった私の両手は 取り戻すことが で きる
If you wish to perform what is written on the scroll, first, the Shinigami is required. It can be found in the Noh mask temple of the Uzumaki clan, in the outskirts of Konoha. First, one must allow the Shinigami of the Shiki Fuujin to possess themselves. The seal can be broken if the belly of the Shinigami is cut. Simply put, it's necessary for me to become a human sacrifice in order to regain my hands that are in the belly of the Shinigami.
In the above part, Oro states that he will break the seal and it's never mentioned if he can pick and choose which souls/chakra he can extract.
The seal is broken, all is free.