Reveal
This is what happened when Qrow unlocked Jacks semblance.
Strength 54 ->64
Battle intelligence 80 -> 100
Vitality 60 -> 65
Charisma 100 -> 120
Worldly intelligence 80 -> 100
Agility 80 -> 85
Aura 200 (Unlocked)
Semblance (unlocked) (Dark version if user is higher or lower in aura than opponent user can switch auras with person. Balance version if users sees two people with a higher and lower aura he can take the higher auras and feed it to the lowers auras until they are balanced. Light version user can use his own aura and feed it to another's aura.)
Dark (Unlocked) (Will be explained later)
Light (Unlocked) (User can activate silver eyes at will to help others or himself against Grimm)
Jack says "Okay thanks for the confidence in me. So what I need you three to do is kill me if I get out of control." "Wait what" Ruby and Yang both day at the same time. Qrow just nodded since he saw the two different auras in him as well as his talk with Ozpin. Jack explains to them how he has two auras a light and a dark and that he can control the light but won't know what happens when he uses the dark. "So I need you three to promise me if I can not control myself that you will put me down." Ruby wanted to argue but Qrow put his hand on her shoulder and nodded his head.
"Promise." Ruby said smiling. "Okay thanks I'm going to back up a bit now and activate it." Jack backs up and focuses on his dark side. It finally activates and Jack starts to contort his body in weird ways as a dark purple and black aura started to visibly surround him. He grows claws on his arm his skin turns as black as the void his soul was in before he came to this world. His feet morph and become hind legs and feet like a wolf or dog. A Grimm mask goes over his face and his eyes turn red and are the only visible feature from his face. He became incredibly skinny as bones outlined the outside of his body. You could feel the darkness coming off of him. The darkness coming off of him was so intense that Salem noticed something was happening but didn't know where. Qrow watching this happened stayed focused and was waiting to see what happened. Both Yang and Ruby has horror on their face but at the same time sadness watching the event take place.
Finally his body stopped transforming. There was no movement from anyone not even Jack in his Grimm form. Until Qrow spoke up "You okay kiddo." But Jack couldn't hear him. In Jacks mind he was to the Grimm version of himself. But while this conversation was going on Qrow asked him the question. This caused Jacks head to turn and bend to the side. He then started to walk over while crossing his legs in front of each other while his arms swing with his walk. As his head would tilt from side to side. Qrow took out his weapon and so did Yang. But Ruby just stood there. Qrow was about to grab her when jack started to charge. Ruby charged at Jack as well. "Rubbbyyy!" Qrow and Yang yelled. Ruby stopped 10 feet in front of Jack as he kept charging. Jack was close enough to Ruby that he swung his claws at her but stopped right before it hit her. Jack transformed back and dropped on the floor on his hands and knees. He looked up at Ruby crying for what he almost did. Ruby tackles him and started to hug him. (Jack cares a lot about Ruby and his close to her already because it was his favorite person in the anime.) He felt her embrace and just started crying out continually just saying sorry.
During this whole event Jack was talking to the Grimm version of himself. "Hey who are you." The Grimm Jack spoke in a raspy creaky voice. "I am you or at least this version of you." "Why can't I control my body?!" Jack yelled. "Well obviously because you called me to attack for you." " No I just wanted to change forms and see what this is like." "Well now you know what I can do. So let me give you a demonstration." As they both hear Qrow. "Wait you can't do that!" Jack yelled. " I can though I'm you. We must kill what is ever in our way. You need me to make the dirty tough decisions." The Grimm Jack said. Jack is now charging Ruby and about to strike her at this point.
"Wait what if we make a deal." The Grimm version of him stops. "What's the deal." Grimm Jack says slyly. "How about this you let me have control of your actions or I guess my actions while I am in this form. For letting me do this. I will let you crush certain enemies by yourself who I view could use someone with your style and cruelness." Jack was trying to fluff his way out of this so he continued. "Imagine us being under the guise of my control to torture the selected people all you want without the consequence of being hunted down for your actions." The Grimm Jack smiles at this idea and said "You know I know your playing but you're right this could be a lot of fun. Fine let's do this. I can always go on a moonlit walk when it happens. Here you go let me know when it's my turn."
Dark (Unlocked) (Lets user turn into Grimm with more strength and agility. Also allows the user to not feel responsible for what happens as he fights in an animalistic style.)
Jack finally calming down stood up in front of the three an explainer what happened including the deal. Jack thought they would be scared of him now but they looked sorry for him as well as ready to help him. Yang said "Don't worry you ever take it to far I will knock it out of you." Qrow continued and said "Well it wouldn't be fair to anyone if the one who found you couldn't take care of you when it happens." Ruby stood silent and turned around to Qrow and Yang and yelled "What are you two saying!" she then turned back to Jack and continued to speak normally "No matter what happens I will pull you out of it by just being there." She started to cry a bit. Jack hugged her a put his tail around her they stood there for a couple minutes then she calmed down. Jack then turned to Qrow and Yang and thanked them. She then looked down at Ruby and said "thank you but I need these two to rein me in if you can't no matter the cost." Jack then patted her head. Ruby just looked up at him and nodded as they headed back home.