The Horus Heresy series is really a stunning bit of franchise architecting like games workshop got their stable of writers together in 2006 and were like alright uoure going to write 50 something novels that'll release in this order, you're getting this plot beat, youre getting this character, you're getting this battle" and for literally 18 years slammed out novel after novel from Horus Rising to The End and The Death Part III that fleshed the heresy out in totality. Crazy