Sm kabuto. Firstly whenever i get into vs threads there is no such thing as plot. There is no such thing as another location apart from where the fight is taking place therefore minato doesnt have ftg tags anywhere else but the battle location.
Anyway due to sm kabuto's enhancements and sm ability increases his reaction speed so much so that its comparable to minato's. Anyway kabuto's first attack rage would cause minato great problems, but also it seems like due to the effectiveness of the technique the opponent cannot struggles to use any form of ninjutsu (itachi did though). If minato was to struggle with such a technique, this alone can end the fight fairly quickly for kabuto, because the only defensive minato has is to teleport to another ftg tag in the cave, but he still wouldnt avoid the technique.
Lets say minato was to survive the first attack.
The second attack muki tensei would prove a great counter to ftg kunai. Basically he has the ability to control the surrounding/objects. Kunai's are tools therefore its fair to say he can control minato's ftg kunai's. If thats the case he can to an extent control the location in which minato teleports. So for example if the kunais are 10 metres away from him. If he was to use the technique and control the kunai and sent them 30 metres away from him and vice versa.
Look at it this way. Lets say kabuto's uses the technique on the cave above minato and minato was to teleport to evade it. Lets say kabuto then uses the techique again to control the kunais, but instead gathers them in one location. What will happen if kabuto then uses the technique again on the cave above minato?, if he was to teleport he would teleport to the kunai's gathered by kabuto and in this instance kabuto can then use the rage technique, because minato is already at the location of the kunai's. He doesnt have anywhere else to teleport.
People might say minato can tag a location, he doesnt need a kunai, that is true but kabuto's still has the ability to control the surroundings therefore my point stands. Secondly minato will not be able to tag kabuto, all of kabuto's abilities due to his enhancements but also oro's ability (body shedding technique) minato tagging kabuto isnt happening
Also note that due to kabuto's medical prowess, sm ability, but also enhancements rasnegan isnt cutting it. Kabuto takes this with mid to high difficulty.