Momonosuke won't kill Ororchi
That's exactly because Orochi's family was killed by Kozuki clan that Orochi wants to take his revenge.
Killing Orochi means Kozuki clan repeats the same mistake.
Oda won't do that
Momonosuke is also still a boy. Even if gets an adult body
A 8 yrs old boy Killing the antagonist ?
Sounds stupid
Momo won't kill someone
No one will die
People become crazy with Killing
On topic : I think Momo will get Ame later
It will show us he trained and become stronger.
I think he will use it in the final war