The 8 Gates

By harnessing the flow of energy within your body you have learnt how to temporarily push past your limits to access a hidden reserve of power and to store away that power as vitality.

Using an action, force your body to consume its reserves and generate Ki. Roll and spend one of your Monk Hit die (d8), lose the amount of HP indicated by the die and gain the following:

1-2: +1 Ki point
3-4: +2 Ki points
5-6: +3 Ki points
7-8: +4 Ki points

If regaining Ki via a rest (Short rest = choice, Long rest = mandatory) and you still have Ki points remaining, double that excess and add them as temporary HP replacing any current Temp HP, then restore your Ki as normal.