Bonesinger

Bonesingers are Eldar artisans, weapon crafters, architects, masons, IT technicians, janitors, coffee brewers, firefighters, yadda yadda yadda. They possess the unique ability to shape the Wraithbone, without which the Eldar would be armless failures.

They practically never see combat, unless a Wraithlord breaks a leg or a Falcon's weapons go derp. Still, they managed to be in Dawn of War as the Eldar builder unit.

Thanks to Made to Order, the old, sexy Bonesinger model was re-released for just one week only. He was also released with free rules, which you can check on the Warhammer Community page. The Bonesinger acts like an engineseer, able to heal units once a turn that have the keyword "vehicle" or "wraith." They can also cast smite, instead.