Ki Pulse is an Additional Stat in Nioh. It affects the initial amount of Ki restored by a Ki Pulse.
You initiate a Ki Pulse by pressing the stance button (R1) after performing an attack, doing so will instantly restore some Ki.
Ki Pulses can be performed as soon as a blue essence swirls around your player, but not every Ki Pulse is an optimal Ki Pulse.
After performing an attack, a white bar will creep over your lost stamina (red bar), Ki Pulses will only ever restore the Ki covered by the white bar.
You improve your Ki Pulse by increasing Skill or Strength. Normally, when you swing your weapon, your red Ki begins to fill up with light blue ki all the way from the left. When you hit an enemy however, part of your Ki will automatically be filled up with light blue. Improving your Ki Pulse stat will increase the amount of pre fill, the amount of the red bar that is automatically filled with a chunk of light blue instantly, before it starts to gradually fill up. This allows you to recover faster.