Recommendation: Past Zero Hour

This is a really fun adventure story! The tales of Regulus the BAMF cursebreaker. Reg is a (legally dead) Gringotts cursebreak and works out tricky puzzles. Also later becomes a nanny for baby Harry. Exciting and generally wholesome story. A little bit of pining in the Sev/Reg relationship, but they figure it out. Updates regularly!

https://archiveofourown.org/works/41160495/chapters/103180302