Jewel of the North, formerly know as vincegetorix
This was how it was presented in the playtest:
You had the base monk, with the usual ki features. Then you had the archetypes Fire, Stone, Air, Heart and Water. Each one add special features based on ki usage. Heart Monks were the one who got Stunning Strike (only once per round in the playtest, by the way) and Quivering Palm.
Add to that Shadow monks (as per the PHB), Solar (XGtE/SCAG) and maybe a Force monk, using the mastery of force discipline from UA Mystic with ranged psionic attacks and you get an awesome class.
Then WotC fumbled it...