So, I had a chance to go through Paths of Waves.
Overall a very fine book, I would say. Sure there is some filler in there: There are complete descriptions of a village and a small town with maps and most important NPCs with stats and all, and I do not really see what they are good for, as they are run-of-the-mill Rokugan places without any relevance. But the book is big enough that there is a lot of more relevant stuff in there, so I'll excuse that.
- The rules and options for Ronin and Gaijin are enough to allow a campaign for them. There is not enough detailed background information to run a campaign in the Ivory Kingdoms or the Qamarist Caliphate, and I would have liked more information on the latter, but it is enough to run a character from there in Rokugan, which is what the book is about.
- There are 29 new kata plus 16 Shuji (plus rituals primarily for Qamarists). The kata are well done insofar as they give a lot of options, but none screamed to me "TAKE THIS NOW". So most are not overly powerful, which is a danger with new material. There are kata for Judo Throws and the Partial Maneuver for mounted archery (riding or running away and still shooting the bow), and while the latter is powerful, that makes sense, as it was a cornerstone of the Mongols conquering the world. Sure, 4 PCs with this kata and daikyu can easily shoot down an Oni while riding out of his reach. But will your group really have that setup? So I was quite OK with the kata. I also appreaciate that there are no new invocations, as there are plenty of those already, and shugenja do not need further boni right now.
- There is a complex mechanism for summoning heavenly artefacts, which is a magical tradition from the Ivory Kingdoms. The artefacts are VERY powerful, but difficult to get, so it seems balanced to me, the GM having the last word. The only omission I could see was that they seem to have forgotten to include the TNs to summon the artifacts.
- The new schools look fine to me. Of course some are better than others. The Ivory KIngdom Dancing Blades gets an Artefact at Rank 2, which sounds too early to me. But the GM can say which, so that should be manageable.
- There is a list of improvised weapons now. Since fighting with improvised weapons uses Martial Arms (Unarmed), they are especially interesting to monks, and finally having a list is thus welcome.
- There are new adversaries: NPC, animals and 13 new monsters. Those were lacking in Courts of Stoneand Emerald Empire, so I appreciate it.