Stage One: Cupil
Cute/Cuprum + Pupil(student)/Pill Bug
Stage Two: Armoult
Argentum/Armour + Moult
Justification: For the first stage, I wanted something simple and cute that included the "KEW" sound produced by Cu rather than the "COO" sound. For the second I really wanted the Armour sound in this name and I think the hard ending gives the right kind of personality.
I'm also liking Birkal's, they sound good (similar to how I wanted my names to sound) and have a good theme