Summoning Kurama

[YellowFang]

Uchiha can put Kurama in a strong genjutsu to make a contract with it... so that they can summon it later...

Only Madara and Obito have shown to put Kurama under their genjutsu, Madara's contract is still intact while Minato removed Obito's contract...

Now, only Madara is the one who can summon it... But when Kurama's sealed, it can't be summoned but it definitely puts some stress on the host...

 

[Gyakusetsu]

Not every summon is necessarily an equitable relationship. The summon can be enslaved by the contract seal and forced to do the bidding of the summoner. This has also been shown to occur by the Uzumaki clan and Edo Tensei is somewhat rooted in these methods as well. How Madara could come to possess such knowledge? It is probably related to the knowledge gleaned from the Uchiha Tablet. The "genius" shinobi all seem able to figure out how to manipulate and create certain techs based upon knowledge of other techs.

 

[VongolaX]

Maybe it's in the uchiha tablet...

 

[itachi uchiha fiance]

they cant do that