Sentinel (слэш)

Bucky Barnes, renowned guardian thanks to his impressive skills, loses more than just an arm in a particularly unusual encounter with Strigoi. He loses his charge's life too and Bucky has always loved Steve like a brother. This is how he finds himself at the Academy.
Tony Stark has always led something of an unusual life thanks to his Royal lineage, but thanks to his jackass father turning Strigoi willingly he's lost all that status. And to make things worse he has unusual abilities that aren't linked to the usual elemental magic Moroi can tap into. Things are only really made worse when Strigoi attacks become more frequent and more unusual.
Rhodey has spent his entire life training to protect Moroi, and more specifically he only has a desire to protect his Moroi. Tony is his best friend and his charge and Rhodey would do whatever it took to keep him safe, even if he's mostly saving Tony from himself.