Expanding on a classic

From the simple caesar to the seemingly uncrackable elliptic curve, there are countless ways to obscure – and even hide – a sensitive message. Cryptography is quite interesting in this way. I find the simpler ones – which are solvable through pen and paper – to be fun little puzzles. The only problem is, once you know how to solve a particular type, it becomes less interesting to solve another of the same. There are a handful of popular ciphers which get published everywhere – beaten to death. The unique, custom one offs are much harder to come by. So, below is my contribution.

This cipher system stands atop the shoulders of another version. It takes a classic to the next dimension, and while I could simply tell you the steps of encryption are X,Y,Z in that order – I find it more satisfying to deduce the method myself than to follow procedure.

You will, of course, need somewhere to start. So hopefully this will assist you.
Sxz pxkd, f- vj-enr, fhjl iyshjklcg ay mttuk. Oq hkbhcix-m rrui rijz ybtubr sxz.

a b c      |  M A E       B G J       N H I
d e f      |  B F D       I A D       L J K
g h i      |  H C J       - L C       M G C
  j k l    |    L G I       E K M       B D -
  m n o    |    N K -       N H F       E F A
  p q r    |    O P Q       V Y Q       S Q Z
    s t u  |      Y W U       S T X       T V W
    v w x  |      S Z V       W P Z       U P Y
    y z -  |      X T R       O R U       O R X

To solve this puzzle, you must decrypt this: XZIUXCFGIJ-QTCA
And give an explanation on the encryption/decryption scheme of the cipher.

Happy cracking!

hint 1:

hint 2:

hint 3:

hint 4:

hint 5:

Solution spoiler: