bloody hate the hurt them to help them trope. Mio, Eri and Prospera have all made/let Suletta become dependent on them and then tried to just cut her loose so she can be "free". Free from what, support?
To be fair, Mio is charging headlong into high level politics amongst major leaders of military-industrial complex with the aim of putting a stop to war, while Prospera is pulling a giant revenge plot with the ultimate weapon aERIal consenting to it. Both trajectories could turn very bloody very fast, so it makes good sense for them to push Suletta off without explanation, since the less she knows and involves with such plots the higher her chances of surviving and living freely. From their points of view, the suffering they are causing her is hard, but the other way could be literal death, so their choices are limited.