The Matryoshka is Laevateinn's aerial-combat ship. It has been built by Alyzanae and her dolls, before she founded Laevateinn itself.
Like it's name might suggest, it has been built from the wreckage of other downed ships that crashed into the ruined Luna during The Calamity. It uses a special engine called The Frostfire to power itself.
The Matryoshka isn't equipped with heavy weapony, instead it aims to be as fast as possible.