Unicorn NTD (S): Required MS
Unicorn (A) -Key, Custom 1
Zeta Gundam (A), Special
Super Gundam (BR), Rookie
Jegan (C), Rookie
Stark Jegan (CR), Rookie
However, I think it should be noted that if you have a Super Gundam, mixing the A rank Unicorn is pretty easy.
Unicorn (A): Required MS
Super Gundam (BR) -Key, Custom 1
Jegan type D (C), Rookie
Jegan (C), Rookie
GM III (C), Rookie
Nemo (C), Rookie
Just throwing that out there. Good luck!