Bit of this Au: Team Minato + Kushina was betrayed by konoha so they went missing nin and later joined the akatsuki. Danzo was trying to find a way to release the kyuubi so he could seal it into one of his root agents in order to “control” it better. Thus he kidnapped Kushina and managed to break part of the seal enough for the kyuubi chakra to leak out but not the kyuubi in itself. Minato managed to make it to Kushina in time but since kushina thought she was dying she started to seal part of the kyuubi into Minato. Though in the end she survived and now Minato and kushina each have half of the kyuubi. Rin was kidnapped by iwa and made into a jinchuriki shortly before konoha betrayed them so she still has the Sanbi in her. Obito was still crushed under the rock and this gave Kakashi the sharingan. Shortly after konohas betrayal team Minato managed to find Obito in the cave alive because of madara though since they were running from konoha nin they did not stay long enough to see madara. Later when they returned to the cave madara was not there and neither was zestu. Essentially this Au is saying, screw canon after rins kidnapping