He hit her. Hoya did not notice that someone came to block Changjo from his punch. He did not notice that the person was Angel. He hit her. He hit the girl he wanted. When he finally noticed that it was her that he hit, it was too late. 

Angel walked around with Jin and Emiko. Jin was to take Emiko home so Angel followed them to the lobby. After they left, Angel made her way back to the lab. That was when she noticed Changjo walking away from Infinite. She was trying to catch up to him when she spotted Hoya grabbing Changjo and proceeding to punch him. That was when she knew she had to act fast. She ran in between the two and blocked Changjo from the hit. Angel was hit in her gut. Since Hoya swung at full force, Angel immediately collapsed onto her knees. 

Changjo didn't expect her to block him. He didn't even know she left her lab in the first place. He caught her before she could completely fall to the ground. He knew how hard Hoya’s punches are. He also knew Angel was very fragile by the way that her members protected her. 
The Teenfinite members were surprised. Why did she block the hit? They thought the Shadows hated them with the exclusion with Himé. Perhaps they were wrong about her. 
“Angel, why did you block that?” Changjo asked her in concern. He was worried that she was severely hurt. 
Hoya stared at her in horror. He hurt her. But his fury quickly took over his guilt. She protected HIM. How dare she protect him when she was supposed to be on his side? Hoya grabbed her from the ground forcefully.
“Yah! How dare you block my hit? Do you like him or something? You're mine! Not his. Mine. Answer me! Who do you belong to?” Hoya screamed at her.
Angel looked up at him in fear and pain. She couldn't answer. She was too scared to. Changjo couldn't stand it anymore. He pulled her back into his arms and glared at his hyung. 
“Back off hyung! Can't you see she's hurt? Can't you see she's scared of you?”
“Nonsense! Stop getting in the way of our relationship maknae!” Hoya proceeded to forcefully remove Angel from Changjo. And that was when a throwing blade was thrown right across his face. He turned to face the culprit who dared to throw something and interrupt him. 
There standing, was Ace and Himé. Rain and Andy stood behind them. They heard the commotion from the meeting room. Himé looked furious. Ace glared at him and kept her hand on her gun. She was going to kill him if he planned to continue. 
“Get the out of this building now before I kill each and everyone of you.” Himé commanded. No one messed with her maknae like that.
“Who are you to interfere with my relationship?” Hoya glared at her. 
“I'm a ing gang leader that's who. That girl you claim to love is my maknae. Now leave before I kill you.” Himé revealed. Chunji looked at her surprised. She was their leader? She looked absolutely furious. Ace, who stood with her, glared at Hoya. She wanted to kill him for touching her sister. 
“Hoya, leave her alone. You already hurt her. Is that not enough for you?” Andy was nervous. He knew Himé meant what she said. However, he was more nervous about the girl standing with her. She had a murderous aura around her. He knew she was an assassin. And he knew that she cared greatly for her members. Hoya would have been dead by now if not for her great control over her emotions. 
“Boss, I can't give her up. She is mine.” 
“Get it through your head! She is obviously scared of you!” Changjo finally spoke. He knew he pissed Hoya off with his words but he couldn't take it anymore. Angel passed out. Ace, who saw her sister passed out, quickly walked up to Changjo and motioned him to hand Angel to her. He shook his head and stated that he would be the one to bring her to the lab. Ace, seeing that she couldn't change his mind, nodded and motioned him to bring her to the lab immediately. Changjo instantly complied. Teen Top went with him and Ace. 
Himé stayed behind to make sure Hoya did not follow. 
“Yah, have a sparring match with me. I think we both need to blow off some steam. I can't promise I won't kill you though.” 
Andy was a bit worried. But he knew he had no right to stop her. Rain looked at his daughter. He knew she was furious. He hoped she would give Hoya what he deserved. But he also hoped that she didn't kill him as Andy was his friend.
Hoya glared at her and smirked after some thought. She would regret threatening him and interfering with his love. 

Changjo carefully placed Angel on a bed in one of the healing rooms. He felt guilty and worried. He felt bad that she cared enough to take the hit for him when she didn't even know him. Ace wasn't stupid. She knew that this kid liked her sister. She wasn't sure that she could trust him though. He seemed like a nice kid. But everyone seems nice at first.
Ace took out her notepad before writing thanks to Changjo. The Teen Top members looked at her curiously. Was she not able to talk? Ricky, being the most direct and shameless, decided to speak his mind. 
“Um, are you not able to speak?”
The members scowled at him. They thought he was insensitive and that Ace would get upset. To their surprise, Ace only nodded at his words. She did not care enough to make a big deal out of it. 
“Um, is it okay if I take care of her? I know you may not trust me but I really would like to tend to her. After all, she blocked the hit for me.” Changjo