If the Sirens don't eat hate they can die of starvation?

[immblueversion 331]

I'm pretty sure they'll live. Negative energy only makes their magic more powerful, and with it their sway over others.

[lunafan3 5]

They can eat human food so they don't need to absorb hate for food. They eat hate as a main food source though and prefer over regular food. Without their necklaces they cant eat hate and are stuck to eating human food.

[SilverComet 170]

I agree with the idea that normal food keeps their human bodies sustained, while the gems are just to absorb power to use their siren forms and junk.

 

 

He did banish them, but I think it was under the assumption that the gateway between the two worlds would be forever closed, or that there would be none after he banished them?

I mean, nothing's stopping them from finding the portal and going through it (as humans anyway), so technically, they might be able to return to Equestria. Unless there's like some magical force that does prevent them?

 

Keeping the sirens from knowing the Rainbooms have two experts in "magic counterspells" is just one part of the "cold war game" both teams play once they became aware of each others potential.

 

The main script restriction in Rainbow Rocks (guiding the plot-a-plot chain resolution), is preventing any situation that could be resolved by "the sirens escaping to Equestria" (where they would cause even more damage than in C.H.S.); because otherwise it would feel like "a next level greater challenge" that was skipped by a lack of confidence from the heroines.

 

From the "bookstory flashback", it is clear that Starswirl banished them without using the mirror (but instead some kind of "Rift" in space).

As long as Adagio´s "scope for control and domination" is restricted in her mind only to their current world, her plans would not involve acquisition of the information regarding "a way to return" to Equestria; because she keeps thinking is not posible.

 

The sirens knew for sure about the mane 7 having "some equestrian magic" in their bodies. But nothing else.

Even if they theorized that Sunset Shimmer was "another monster from Equestria" banished to this world (because of the she-demon thing); they had no way to prove it, since equestrian magic can transform both normal humans and aliens.