Montgomery A Box seems to have confused this Initiate with someone else's Cultist, so let me just review this properly.
The Initiate is a martial artist base class for Dungeon World - a little bit like the D&D Monk, but less overtly supernatural. The starting moves give you a signature combat style that you get to pick tags for much like the fighter's signature weapon move, the ability to run across water or walls like a wire-fu character, and a move that lets you attack the enemy's pressure points to disorient them or disable their weapon arm rather than doing damage.
The advanced moves are a mixture of moves that add a supernatural angle (ki fireballs, absorbing the powers of magic items into your fists, having skin that is nearly impossible to pierce), moves that make use of the often-forgotten bolster/preparation mechanics, and more traditionally martial-arts-y moves (teaching others how to fight - appropriate called "Sweep the Leg" - or else being better at fighting foes who've previously defeated you, studying the enemy's fighting technique or using the environment as a weapon).
All in all, the Initiate is a good class - it's well-written, fits in with the core Dungeon World classes both in terms of how it's written and how powerful it is, and it offers a variety of original moves (apart from the multiclass move, none of the moves are taken from any other playbook - they're all specially written for this class). Whether you're specifically looking for a DW take on the D&D Monk or you just want an additional playbook for your DW campaign, this is a good buy.