to indulge momentarily in a spiral of true conspiracy… if the white void is in fact, for whatever reason, Karkat’s womb-home, then it makes sense that Echidna would require Karkat’s presence in her womb-lair in order to complete her deal with the heroes. and if Karkat’s presence in Echidna’s lair is parallel to the moment Slick first observes him in his room, then when Echidna says she “just wanted Karkat there” to complete the transaction, her request was probably actually that “This young troll stands in his respiteblock.”
and since we can view Calliope and Karkat’s meetings with the Dead Cherub/Echidna as mirror images of each other, when Calliope asks the Dead Cherub “what shoUld i do?”, she’s really asking the question that accompanies a young troll standing in his respiteblock; what will you do? to which the Dead Cherub responds, of course, “live.”
Calliope follows this advice immediately afterward by donning the ring of life, thus making the command to ‘live’ read more literally as 'become alive’… so in the context of Karkat, 'be born’? hrm.