Probably because it uses too much chakra.But in the other hand that doesn't make sence.Yamato was neither senju nor uchiha but he can use it in battle.Obito having both uchiha and senju dna should have been in a complite differnet level.
Probably because it uses too much chakra.But in the other hand that doesn't make sence.Yamato was neither senju nor uchiha but he can use it in battle.Obito having both uchiha and senju dna should have been in a complite differnet level.