Give Life. As a bonus action, the Psiw-o-Lliw can target one creature it can see within 5 feet of it that has 0 hit points and is still alive. The target regains 10 (3d6) hit points.

Ephemeral. The Spiw-o-Lliw can't wear or carry anything.

Incorporeal Movement. The Psiw-o-Lliw can move through other creatures and objects as if they were difficult terrain. It takes 5 (1d10) force damage if it ends its turn inside an object.

Variable Illumination. The Spiw sheds bright light in a 5- to 20-foot radius and dim light for an additional number of feet equal to the chosen radius. The Spiw can alter the radius as a bonus action.

Freeze. Melee Spell Attack: +4 to hit, reach 5 ft., one creature. Hit: 9 (2d8) cold damage.

Invisibility. The Spiw and its light magically become invisible until it attacks or uses its Give Life, or until its concentration ends (as if concentrating on a spell).

Anti-Wisp. If the Spiw is within 5 ft. of a Will-o-Wisp, it can take an action to force it to make a DC 17 constitution saving throw. If the throw succeeds, then both creatures lose half their hit points, rounded down. If the throw fails, both creatures disappear in a burst of smoke.