Date A Bullet: Dead or Bullet

Both are similar in the sense that they're both spin-offs about the most interesting character from their own respective series but they were somehow put into really uninteresting stories that leave much to be desired.  

Both shows are very colorful and have amazing backgrounds. Both are worth watching if you like fantastic visuals. 

"Magical Girls" forced into a battle royale death game type of thing where they have to fight to the death until only one is left standing.