Let me explain this the best way I can for you miss winter
Spiritus is a mass of shadow that jack creates and controls like a puppet,this puppet is shaped like a nightmarish humanoid,has razor claws,an odd face and a hood to cover it,the spiritus's right arm and left leg appear to be severed but move with the body as if attached,jack is unable to use his power in another way with spiritus active because he needs to focus all his attention are else something would snap,for example spiritus could flip vertically is jack were to react to a hammer hitting the floor,if jack summons dreadsickle before spiritus is summoned,he can make spiritus hold dreadsickle

If there is something else your unsure of I will try and clarify,also spiritus has no CS