𝙿𝚘𝚙𝚞𝚕𝚊𝚛 𝙼𝚊𝚕𝚎𝚌 𝙵𝚒𝚌 𝚃𝚛𝚘𝚙𝚎𝚜 (10/?): Angels & Demons 𝙰𝚄

Where Alec is an angel and Magnus is a demon. Sometimes heaven commands Alec to chase Magnus for his sins on earth. Other times, Magnus tries to tempt Alec or they just have a forbidden love. Every time they fight against heaven and hell to be together. Possibly they also try to stop the apocalypse. Hallelujah!

Also, this trope could include all the fics where Alec has wings, Magnus is more demonic or inherits Edom.

𝙿𝚘𝚙𝚞𝚕𝚊𝚛 𝙼𝚊𝚕𝚎𝚌 𝙵𝚒𝚌 𝚃𝚛𝚘𝚙𝚎𝚜 (8/?): Reverse 𝙰𝚄

Where Alec is a warlock and Magnus is a shadowhunter. The character roles are all inverted (shadowhunters are warlocks and vise versa) but storyline follows canon. They conserve their original personalities so Alec is a grumpy hermit and Magnus loves flirting and fashion.

𝙿𝚘𝚙𝚞𝚕𝚊𝚛 𝙼𝚊𝚕𝚎𝚌 𝙵𝚒𝚌 𝚃𝚛𝚘𝚙𝚎𝚜 (7/?): 𝙰𝚛𝚛𝚊𝚗𝚐𝚎𝚍/𝙵𝚘𝚛𝚌𝚎𝚍 𝙼𝚊𝚛𝚛𝚒𝚊𝚐𝚎 𝙰𝚄

Where the clave and the downworld are in figthing and for make peace they arrange a marriage between a shadowhunter and a downworlder. They usually choose Alec because his family lose his power in Idris since his parents where in the circle, and they choose Magnus because his one of the most powerful warlocks alive.

Other times the war is already over but the clave needs to do a social peace declaration with a political marriage.

A few cases include one of them being a war prisioner but in general Alec is really open minded and acept Magnus’s culture. They find love in each other so they stay together.