Alec had broken Magnus's heart, but he had noble intentions. It was the only way that Asmodeus would give Magnus his magic back.

Magnus had joined forces with his father in his heart break, Asmodeus had taken the opportunity to strike.

Clary, Jace, Alec and Izzy had all been Kidnapped by Asmodeus.

Where are my manners, I am Magnus's sister, Tess Bane. Unfortunately we were separated a birth and by separated I mean that Asmodeus had given me to Lilith as the price of a deal, which means Magnus and I have never met, he doesn't even know that I exist.

For years I had been watching my brother live his life on the earthly plain, I watched him be manipulated by Asmodeus and I vowed to never let that happen again, so when I saw that Asmodeus had kidnapped his friends and Magnus wasn't trying to save them I knew I had to do something. I walked into the room to see Magnus watching our father invading Alec's mind.

"ENOUGH!" I boomed as I pushed Asmodeus against a wall with my magic.

 Magnus turned to look at me.

"Well, hello Tess, What brings you here?" asked Asmodeus

"I came to stop you from hurting Magnus...Again"

"I would never hurt him" he said

"Oh really so he knows about the deal you made with the Lightwood boy?"

"Father?" questioned Magnus

"He was the one who made Alec break up with you, not three nights ago at that dinner he arranged for you, he was going to give you this" I held up the Lightwood family ring "He was going to propose Magnus, he loves you more than anything and I think you know that"

"Why should I believe you?"

"Because you and I are the same, see?" I said showing him my cat eyes.

"That's... impossible"

"When I was a baby, he made a deal with Lilith, the price of the deal was me. Your my twin brother Magnus and I don't want you to throw away the only thing that makes you truly happy" "I know you Magnus, I have watched you for many years, unable to meet you, It was torture, If you throw away your love with Alec, you will be throwing away the greatest thing that has ever happened to you"

"I...I..."

"This isn't who you are Magnus, Asmodeus is manipulating you, just like he did before, don't let him do it again, you can beat him, you are stronger than you know"

"Don't listen to her son, she is a liar" said Asmodeus who I was still holding against a wall.

 Magnus realised that I was right "No father, you are the liar, you manipulated Alexander, made me turn on my friends and worst of all you made me believe that I was alone all this time, for hundreds of years you made me believe that no one cared" Said Magnus as he wrapped Asmodeus in magical bonds.

"You will always be alone"

"No he won't" I said "He has me and them" 

"You are weak, both of you"

"No father, you are the weak one" replied Magnus

"You are weak just like your mother, she didn't even put up a fight"

"What?" asked Magnus, both of us were confused.

"Did you really think she would abandon her Son?"

A single tear fell from Magnus's eye as his anger got harder to keep in check. He used his magic to pick up Jace's serif blade and hold it to Asmodeus's neck.

"Magnus don't" I pleaded as I stood next to him.

"He killed my mother, our mother he deserves to die"

"Magnus, you are not a killer, not anymore, he wants you to be like him, to be evil, but you are not like him, you have to be better than him, you are better than him, please Magnus, don't do this"

Magnus screamed into the air and dropped to his knees, Asmodeus still tied up. I hugged my brother as he cried.

I stood up and opened a portal behind Asmodeus.

"Do you know what happens when you enter a portal unconscious?" I asked him

"Limbo..."

"You have caused the both of us enough pain, now what ever happens to you, you have to face it knowing that you were beaten by us, Goodbye...father" I said as I used my magic to knock him out and push him through the portal.

I went back to Magnus who was still on his knees.

"Magnus?" I said as I kneeled down in front of him and put my hands on his shoulders.

"He killed her" He whispered

"I know, I'm so sorry, I wish I had the chance to meet her"

"Magnus?" said Alec who was still tied to the wall with the others.

Magnus and I stood up, he wiped his tears and turned around to face Alec.

"I'm sorry Alexander"

"You don't need to apologise, that should be me"

I let Magnus and Alec talk while I used my magic to set the others free from their bonds. When I saw Magnus and Alec hug I knew my brother would be okay, he had found a family, people to love him for who he is and I will always be thankful for that.

"Thank you all"

"For what?" asked Izzy

"For loving my brother"

"I'm sorry Tess, If I had known..."

"Its okay Magnus, I am so proud of you" I said Hugging him.

"So this proposal?" asked Clary

"Yes" said Magnus

"Wait, what?" questioned Alec

"Alexander Lightwood, will you marry me?" asked Magnus 

"Only if you'll marry me too" replied Alec 

I handed Alec handed the ring and Magnus used his magic to create a second identical ring and put one on Alec's finger then Alec put the other one on Magnus's finger.

Magnus, after all his heartache, had finally found a family to care for him as much as he cares for them and Tess could not be happier for her brother.