TMZ
      +--------
JJZPT | PRNYLTV
       -PHZHM
        =====
         MWYNT
        -MLZQQ
         =====
          YHTXV
         -ZZLVU
          =====
           TJVQ

base: 16
letters: GHJLMNPQRTUVWXYZ
difficulty: challenging
missing: G