I didn't see similar strategy online so I wanted to share my take on Libromancers. Deck isn't fully finished so feel free to play your own variant of it.
Optimal play is 3-card combo: Diviner of the Herald + Emergency Teleport + LM ritual (preferably lvl 3 or 6). Normal summon Diviner and send Arc Light to the GY and Search Benten. After that play E-Telly to SS Geek Boy who searches field spell. Field spell to LM Fire than search Doombroker (or Firestarter). Ritual summon using Benten from the hand and set a LM Intervention, also Benten searches Vanity's Ruler. After that ritual summon other Libromancer ritual monster using Diviner who ss Angel o1. Angel o1 gives you extra tribute summon which you use to put Vanity's on field using it and Geek Boy. Then you can link summon Linguriboh using Fire for extra protection from Imperm. And that's pretty much it.Deck is build around it so you have other tech cards like 3of Preparation of Rites. You can even play 2-card combo but then depends what other cards you have in hand.
Going second is best to disrupt opponent as much as you can and then go for LM Fireburst via LM Bonded.
P.S. I hope we will get LM lvl5 ritual