I think i know why madara doesn't want his boyfriend hashirama to help fight obito

[The Leafs Legendary Duo]

I say this cause as we are now aware thanks to the all knowing tobirama obito can nullify all ninjutsu which also includes edo tensei hence why tobirama told minato to be carefull not to take anymore damage cause he won't be able to regenerate basically meaning that even though minato and the other hokages are edo and edos are supposed to be able to take any damage and regenerate if they get hit by obitos balls they will die and madara is probably mysteriously aware of this hence why he won't let his boyfriend fight cause well hashirama is an edo and if obito destroys hashirama with his balls or whatever he will be a goner and madara will be bored and will be back to square 1.

 

[ClydeFrog]

Could be that, or the slightly less gay reason that everyone else has been discussing, which is that Hashirama is the most powerful Sage Mode user in the bunch, and Madara somehow knows Senjutsu hurts Jubito. Either way both theories require Madara to have insight on Obito's current abilities, which is strange.

 

[Bantos]

It's the big black staff and balls.

 

[DeadManWonderLand]

Could be that, or the slightly less gay reason that everyone else has been discussing, which is that Hashirama is the most powerful Sage Mode user in the bunch, and Madara somehow knows Senjutsu hurts Jubito. Either way both theories require Madara to have insight on Obito's current abilities, which is strange.

It is not strange at all
Madara is the one who deciphered the tablet and learned the secrets of rikuudo by learning yin and yang,yin-yang,unlocking the gedo statues from the moon and starting this whole plan to begin with.

 

[AzR]

because~~ with his mokuton plus with his senjutsu... it definitely can hurt obito in some way