What she says: I’m fine.
What she means: Somebody please make a Shadowhunters fanfic where Magnus or someone sends Alec to a different universe to save Magnus (from a different universe (like maybe there is a demon wiping out all of the “Magnuses” or Magnus somehow got thrown into another universe with his memory wiped)). Magnus happens to be Mike Chang from Glee in this universe. Que all the girls falling over Alec because I mean come on, have you seen him? (And he is weird, awkward and quiet). And Alec is so freaking confused because Mike is dating Tina (and he thought this “Magnus” would have his memories, or he gets jealous because Magnus is with Tina). And Mike Chang/ Magnus thinks Alec is weird because this kid is trying to convince him that he is Magnus (from SH) but he also feels compelled/ drawn to him/ intrigued, he ends up falling in love with Alec just as the original Magnus did? I mean picture Malec fighting in middle of hallway… Mike screaming, “ I don’t know what you’re talking about! I don’t know who you are!!!” Alec has to convince this Magnus that he is the real Magnus so he can bring him back to the real world… In heated moment, maybe toward end, Alec pushing past the student body trying to reach Mike from across the room. Alec is covered in blood, dirt and grime- he just killed a demon, Mike lets out a surprised, “Alec? What the hell ha-” Alec pushed Mike against the wall, kissing him forcefully (everyone losing their minds, Finn, Kurt, and Blaine made a bet against each other regarding Alec being gay, which now Finn and Kurt are handing Blaine money). Mike and Alec pull apart as Mike’s eyes light up, Magnus’s memories flooding back to him and recognition washing over him as he stares into Alec’s eyes lovingly, “Alexander? What was that for?” A smile breaks out on Alec’s face as he realizes Mike is now Magnus, “I couldn’t think of any other way to get you to remember.” Maybe other demon shows up- epic fight scene.
Also, Alec looks exactly how he normally does- runes, black attire and awkward attitude- Everyone suspects him of being in a gang, some are afraid to talk to him at first because they think he is mean/ hardcore but really he’s just a quiet mushy awkward clumsy teenager. Puck feels intimidated by him, Quinn and Rachel hitting on him along with (Brittany and Santana? before they got together) (Alec is oblivious of course). Demons show up and everyone is starting to think that Alec is losing his mind because he has to fight these *invisible* demons (The other characters can’t see them because the demons are not from their world, maybe a scene a few chapters in where Mike, Tina, Alec and another glee person get locked in the school after hours…) They split up, Alec and Mike get trapped in a room, Alec asking questions about Tina, implying Magnus…. “I just- so- so like what do you see in her?” Alec asked quietly, gripping at the stele hidden in his pocket. “What! Dude is know really the right time!” Mike yelled as the demon creature inched closer… Mike/ Magnus sees demon for first time- thinks Alec is crazy, “Stay away from me you freak!” Mike yelled before turning back towards Tina to see if she was okay. Alec Jealous….
And maybe when Alec returns back to his universe (maybe hurt or out of it) he asks Magnus to sing to him because he heard him sing in Glee (watching Mike/ Magnus sing, dance took his breath away… idk maybe Alec awkwardly is recruited by the Glee club which he obliges in order to get closer to Mike to convince him he is Magnus and to protect him, maybe he is forced to sing (maybe he can sing, idk, your choice)). If we work on the memory loss and Magnus being thrown into another dimension theory, maybe he loses Mike’s memories when he returns to the SH world, so he is slightly confused but hoping to ease his BFs pain he complies.