In the English version of Ch. 21 on page 9, the translator has a note of "I don't get it". Unfortunately, a lot of the story is written from Yoshitsune's viewpoint, and he tends to ignore a lot of Epsilon's explanations and important tidbits, so in this scene Yoshitsune is realizing that Epsilon has been trying to fight the system, aiding and guiding him while staying within her bounds.
Epsilon is overtly hinting how Shinano and Suzuri can be freed from [Control], which was placed on them under the authority of Greece, who seems to be the highest system authority. Sky Forest is largely outside of Greece's influence, which means that [Control] will not function in Sky Forest, along with any other restrictions that Greece might have imposed.
The properties of the mental suppression aspect of [Control] have not been made clear. Epsilon first calls it a mind suppression operation or procedure, and states that once completed, forcefully canceling or nullifying it would almost certainly lead to injury. Epsilon probably meant this in the sense of using an exploit to circumvent Greece's influence. Yoshitsune assumes that Epsilon means their personalities are completely erased and gone forever, and does not think to query further if there might be an in-system method to properly dispel the condition. We later learn that there is a history of some heroines who leveled high enough to resist and break [Control] and recover their personalities, but heroines are not generally allowed to level, so it is not known if this is universal at a certain level, depends on the level difference to the original caster, depends on the person, or requires a skill (like one that resists mental status effects). Yoshitsune does note that Shinano and Suzuri seem to have become more expressive after gaining some levels. Most likely, once in Sky Forest, Epsilon can completely remove [Control], but this may depend on Yoshitsune having management rights.
Shinano's [Copy Doppel] was not a lifeboat skill for her mind. Rather, her copy was able to continue interacting with Theta, and so she was able to avoid a pregnancy. There may be skills or items that can harmlessly dispel [Control]. And as per the trope, Yoshitsune worries that Shinano and Suzuri might harm themselves after remembering all of the rape (assuming they remember it), or they might hate him, and he also ponders if they might require multiple visits to Sky Forest, like a treatment regimen.
And it is very clear that Epsilon, Theta, and Omicron do not like the current situation and are working against Greece, who might also not like the current situation but is being forced into it by the royal family. It also seems that Yoshitsune's head will soon be sticking very high above the floor, and confrontation with the royal family seems highly likely. One of the important tidbits about Astro King that Yoshitsune ignored was that it should have the ability to interfere with the summonings, and may have the ability to get everyone back home.
