Einherjar

You sacrifice half of your max hit points to shape an illusory duplicate of yourself. it can take actions and otherwise be affected as a normal creature. It appears to be the same as the original, but it has half the casters hit point maximum, is formed with a copy of your equipment, and has a Astral glow. Otherwise, the illusion uses all the statistics of yourself.

Einherjar is friendly to you and creatures you designate. It obeys your mental commands, moving and acting in accordance with your wishes. acting on your turn in combat, Einherjar will move like a after image, repeating your actions targeting the same target. Einherjar lacks the ability to learn or become more powerful, so it never increases its level or other abilities, nor can it regain expended spell slots.

Einherjar lasts until it drops to 0 hit points, at which point it vanishes.