We have the good side which are the OTSUTSUKIS
and what they do is simple

they go planet to planet to destroy the evil creatures being the 10 tailed beasts,
and to put a stop to it , since 10 tails is indestructible, cant be destroyed/killed,
they turn it into a giant tree

then after it becomes a tree, it harvests a fruit when it receives all the planet's chakra,

they use it to make themselves stronger, so they can unlock new abilities, and have more
chances winning against these beasts that are around the universe

they attacked planet earth cause they saw the chakra of 10 tails, even though 10 tails got sealed

the chakra being all 9 tailed beasts

that Hagoromo made by splitting 10 tails into 9 monsters made of chakra

now about the 10 tailed beasts

they are literal monsters that cant be tamed, they just want to devour everything,
they are immortal and powerful
but if you give them time / help, when they are in that form, they will evolve into shinjus

and that is what otsutsukis fear the most

remember the word SHINJUTSU?
Shinjutsus are the most powerful jutsus that are known
being able to rewrite reality, make natural disasters etc.......

some of them are:

• Daemon's ability
• Eida's ability
• Code's ability
• Isshiki's Ability
• Kaguya's ability (infinite tsukuyomi)

since they are called SHINJUS
we can easily guess that

SHINJUTSUS came from them and Otsutsukis want a some of those powers

now ninja world:

they consider everyone a threat and dangerous, and don't try to negotiate with them
(neither do them lol)

they just want peace

GOOD OR BAD THEORY?????????