Does Somni Wing restore EP to the team?

Eternal Lightwave raises EP recovery by 31% for every teammate, not just whoever is on the field. That makes Somniwing a battery rather than a damage dealer: its job is keeping your EP-hungry Aniimo able to use their abilities more often. You will also see the skill called Light Wave or Ethereal Light Wave. It is the same skill.

Its ultimate adds a direct refill on top, recovering 50 EP. Hold it for the moment a rotation runs dry and use it to top the team up mid-fight. The rest of the kit also raises maximum AP.

Timing matters. Apply the regen early, before the fight starts or before you switch to your main damage dealer, so the boost is already running when the expensive abilities come out.

Which teams want it, and how to build it

Somniwing pays off in teams that burn through EP: Grass, Irisalis and Egg Heist teams, and the Hexing build, which uses it as its energy support. In Irisalis teams it handles resource management through Eternal Lightwave.

Build it for maximum regen and put its capability points into regen. Damage is not what it is on the team for. You cannot catch one in the wild; it is the reward for reaching 180 Elite Training points in the menu.