I think it's a tense problem but I could be wrong. It's more of a "Who" is making the answer type of thing.
"unless it needs it" - Usagi"Unless it is needed" - Serenity
Both give the same information, one sounds like it is coming from an adult.
I would be more prone to say that Usagi has a similar problem to Zeke's with her "Imperial" personality, except that they (Usagi/Serenity) are the same person. with the Serenity Persona being the more Formal/Mature, to Usagi's Schoolgirl.
But then It's just me.
"unless it needs it" - Usagi"Unless it is needed" - Serenity
Both give the same information, one sounds like it is coming from an adult.
I would be more prone to say that Usagi has a similar problem to Zeke's with her "Imperial" personality, except that they (Usagi/Serenity) are the same person. with the Serenity Persona being the more Formal/Mature, to Usagi's Schoolgirl.
But then It's just me.