A/N This is my first attempt at a TMI fic and I hope it went well! I can not wait for City of Heavenly Fire to come out!
Disclaimer - I don't own any of this - all characters and events belong to Cassandra Clare!
Alec had always been the sensible one. All through his life he had never been the first to speak and he was never one to make snap decisions. If he didn't know you he would barely tolerate you until either you left or you forced your way into his heart. There were very few exceptions to this rule.
An obvious exception would be his parents. Maryse and Robert Lightwood had always expected a lot from their eldest child, but they loved him. He wasn't officially trained until he was 12 but as he grew older he realised that his parents had left the door of the training room open just wide enough for a small child to slip through, and that his mother had given up practising the bow once she knew he was better than her. One of his best early memories is when he got the flu and instead of calling a warlock, his father and mother made him soup and curled up in his bed with him and told him stories. As he grew up, he put off telling his parents he was gay because he didn't want to disappoint them. Eventually though he came out, and though his father was shocked (his mother said she had known all along) they both understood eventually. They met Magnus and, although they don't really understand each other, they're friendly and they approve of him which is all he can ask really.
Another exception is Isabelle. From the first time he held her tiny body Alec knew he would protect his little sister with his life. Even know, when he knows she is lethal with that whip and is a better fighter than him, there is still nothing he wouldn't do to keep her safe. He has always thought that that was one of the reasons his parents felt so safe leaving them alone in the institute. Alec learnt quite early on in his life that no one can keep Izzy from doing what she wants to do. So, while he knows he can't stop her from going to parties and getting drunk, he can cover for her with their parents, and he can provide painkillers in the mornings (from personal experience he knows that the while the iratze helps with their shadowhunter injuries nothing can beat mundane painkillers for hangovers). He also knows he can not stop her from recklessly giving her heart away to any boy that bats their eyelashes and promises her anything, he can give her ice cream and sit with her while she cries. When the were younger he would try to persuade Jace that they should leave her behind when they went hunting, not because he didn't want her there but because he knew if she got hurt he would never be able to forgive himself. Every time they go to fight Alec has to entertain the idea that one of them will not come back and each time he comes to the same conclusion - if someone is not coming back it will be him. Not because he is the worst fighter – although he knows it's true – but because he will keep them safe no matter the consequence.
The next person to make their way into his heart was Jace. When Jace arrived he was a small solemn child who Alec and Izzy ignored. Somehow the golden child forced his way into Alec's heart and refused to leave. They were parabatai and were closer than brothers, more than best friends until Alec thought he was in love with him. Jace didn't know why but he was losing his brother and during that time it was (for once) Jace clinging on to Alec. But then Jace found Clary and Alec found Magnus and they became brothers again. Their friendship had gone back to the easy way it was before, but still Alec knew he would protect him. Jace was the best shadowhunter Alec knew, but he was an adrenaline junkie and he would play with the demons. Alec knew that Jace was reckless and so he had accepted long ago that one day Jace would do something incredibly stupid and Alec would probably die from it.
But Alec should have protected Max. Max with his too big glasses, which always slipped down his face, Max with his seriousness and delight in learning new things. The little boy who had delightedly explored every crevice of the institute while they were training. Alec and Max had never been that close – there was too big an age gap between the two, and Alec had always had to act like his parent because Maryse and Robert were never there. Alec was ashamed to admit that he as a little jealous that the youngest Lightwood was always taken with their parents when they visited Idris. But while Max had chosen Jace as his hero, whenever he needed reassurance or comfort he would inevitably end up at Alec's door. Alec can't count the number of times he heard a small knock on the door and a teary voice saying 'Alec? Are you awake? ' Soon after that a tiny, cold body would slip into the room and curl up next to him. Max had trusted him to protect him from the monsters in his dreams but Alec had done nothing to protect him from the monsters in real life. Alec had fought tooth and nail against his parabatai to delay Max's training. He didn't care how bored Jace was, there was no way his little brother would start learning how to kill demons yet. But Alec had left Max alone with that monster. It was his fault Max had died and he'd be damned if he lost anyone else after that. He missed his little brother every day. He would hear the rain on his roof, and mistake it for the quiet pattering of Max's feet as he ran to show them something new he found. He would lose a book and expect Max to have it. No one had entered Max's room and Alec doubted anyone would. Alec would protect his memory because he would do no more.
Magnus had erupted into Alec's life bringing excitement and glitter in his black and white world. Alec had thought Magnus was joking when he first winked and said 'Call me'. However each time they bumped into each other Alec became more and more attached. Strangely he never treated him as badly as he did other newcomers in his life. He had been surprised at himself when, at their first meeting he had said 'You can't help how you're born", showing compassion to someone he barely knew was rare, without even taking into account the fact that he was a downworlder. Even though Alec knows Magnus is a big, strong, all-powerful warlock, Alec knows that he would do anything to help him. He knows it's irrational as he isn't stronger or quicker – he knows that the only thing he can ever do to save Magnus is to get in the way of a sword or a spell, even though Magnus would probably hate him for it. But unlike the others Magnus understands. He doesn't complain about Alec being unwilling to let him out of his sight for too long after what happened to Max. Magnus doesn't complain about the late night (or early morning) phone calls he always gets when Alec stays at the institute. Instead they chat until Alec falls asleep. Alec also knows that Magnus will protect him, and Magnus is the only one he trust to protect him. Jace and Izzy are too reckless and his parents are never there but Magnus will always protect him – always look after him. And Alec knows he doesn't want any more than that.