ASHES OF ONYX by Seth Skorkowsky is the first of a new series by an author I've very much enjoyed the previous works of. I'm a huge fan of the Valducan series, which is a set of novels following multiple protagonists wielding magic demon-slaying weapons. I'm also a Tales of the Black Raven fan, which is a collection of compiled short stories featuring a master thief. Finally, I love Seth Skorkowsky's many Youtube series that were winners of an ENnies Award last year for best game reviews.
Sea of Quills is the sequel to the extremely successful Mountain of Daggers book by Seth Skorkowsky. Both are part of the Tales of the Black Raven series, which follows the adventures of Ahren, a sailor turned cat burglar who has managed to become the world's most infamous rogue. The books are set in a Hyborian-style fantasy setting distantly related to the Renaissance but including many qualities from other time periods as well as both monsters and magic.
REDEMPTOR by Seth Skorkowsky is the latest of the Valducan series. I'm very fond of this urban fantasy series and its premise: that there is an organization of monster hunters armed with magical weapons that allow them to kill the hundreds of demons afflicting the Earth. Each book has a different protagonist but often has guest stars of the original cast. This book, Redemptor, is unique in that it is named after a villain's weapon rather than one of the heroes' weapons.