Why do they unleash their most powerful jentsu when they are most beaten down at the end of the fight? Doesn't it make sense that they would start powerful and then wind down? Or is the strategy to take minimal dmg while inflicting enough dmg on the opponent using limited jentsu so that when you use your ultimate jentsu the opponent is finished but you are left on the brink of destruction only? Make sense. answer NOW!
shareIt's just manga bullshít, but if you want an in-universe excuse, how's this: these ninjas take lots of resources and time to train and so, they are expected to do many missions before they get killed. So, they must hide their trump card lest the enemy country/organization develop a counter to it.
Think of Itachi. If Orochimaru knew about Totsuka, he could've invented a counter to it, such a using clones or Edo Tensei.
Also, some of the most powerful jutsu are also dangerous to the user. Mangekyo Sharingan or Shiki Fuujin (Death God), for example. Also, thye use lots of chakra.
There are other reasons too, like Sasori's jutsu. He probably couldn't use his more powerful jutsu while wearing the armor thingy.
My name is a killing word.
Even if that is the logic, it doesn't bug me.
RIP
Jeff Hanneman
1964-2013