Why would you need it even though you wanted to see Nito in the first place and now she is right before you, Mokou? So you just wanted to become immortal after all?

It's possible that she wants to give it to the guy so he can do what he was supposed to do and get rid of the elixir, I suppose...

Qpax said:
Why would you need it even though you wanted to see Nito in the first place and now she is right before you, Mokou? So you just wanted to become immortal after all?

She probably just got herself so fixated on getting the elixir that she can't think straight. The means to an end is now the end, etc.

Pumpkin_Eater said:
She probably just got herself so fixated on getting the elixir that she can't think straight. The means to an end is now the end, etc.

Or she simply knows that eventually Nito MUST return to the future,leaving her alone.