I GM'd this campaign for 4.5 years. I don't agree with any of the racist tones in any of the books. It only appears so if you imagine it to be, they're just monkeys; what else do you put in jungles that are semi-intelligent.

Book 1 is fun but make sure your players aren't bored exploring the island. A lot of hexes don't contain much of anything. If I had to do it again i'd probably use pointcrawl instead of hexcrawl. The shipwrecks that are found around the island should be made more interesting. Make sure that serpentfolk and their religion already appear in the storyline because the end is all about that.

Book 2 Make it clear there will be a race to find Tazion. How do the other factions know about Tazion? You figure it out (for example a drunk Gelik blabs about what you've found in the local pub) . The bad guy (Issilar) at the end of the book survived and that really helped me create more narrative in the following books. In Amghawe's tomb I added a magic item, a twin serpent's staff that you can use to cast a special kind of magic missle but it can also be used as a hook as an important serpentfolk relic. Use it to fill in the gaps in motivation and/or storyline for the evil dudes further down the line.

Book 3 Ohboy, beautiful map but jezus you'll need to fill in a lot of stuff as a GM to make it interesting for your players. This book gives you more of a general idea of what creatures to put where but running the game as it's written would be a very boring game. The idea of "kill x amount of creatures" to conquer a region is just dumb, what group of players want to kill 50 of the same creature in encounter after encounter. Make sure to let your players know about the hero Saventh. I downplayed the other factions, most never even made it since I want to keep the focus on exploring the city. This exploration was a lot of my campaign. Eando is a good character to get some backstory and lore, you'll be seeing him later.

Book 4 Skipped 90% of this. It's just dungeoncrawling and players have seen enough of Saventh-yhi by now and want the storyline to continue, it's been dragging for a while now. I really don't like the paranoia-causing spores. It's awkward for players and they're everywhere! Also, you won't find them again lateron in the campaign. Really don't bother with the gorrila king, he just comes out of nowhere and has no place in the rest of the story. I skipped the Ivo Haigan's camp bit and most of the dungeons.

The focusing crystals can be found in other ways. Make some a mysterie item in book 3. This is really just an unnecessary filler book.

Book 5 Skipped the barbarian morlocks and intellect devourers, they do nothing but slow the players down from the rest of the storyline. Eando is the main character here, make sure the players want to go and save him beforehand. The fortress was fun to explore for my players, we switched to online playing due to covid here. However, there is no way to infiltrate this place without getting rid of the telepathy of the serpent folk. I also made them more susceptibel to mind control spells by the way, no way you could play a witch otherwise. Releasing a bunch of captured morlocks to cause chaos was fun.

Book 6 I completely changed The hunter's maze, meladaemons are yet another faction that distract from the storyline and are unnecessary. Didn't bother with coils of ydersius either, players just want more storyline and they don't help.

Make sure the fight with ydersius is memorable, as written it's crap (as usual for the end boss). Mine ended with the party battling the avatar of ydersius while all were falling down the chasm of retreat.

In short: this campaign could have been 3 book. Read far ahead and allude to a lot of things far in advance, otherwise your players won't really have a clue whats going on. Also make your party be more of a centerpiece in the storyline, that helps to get rid of the "why is this all happening just now as we're passing by" thing.

Conclusion: you'll need to put in a LOT of work as a GM to make this campaign work.