That was as easy as it can be. I had to use Olhydra stats for the final boss to make this fight at least worthwhile. Too easy for Tier-4 adventurers. The Loot is good though )

Felt like a decent introduction to tier 4, aka we can ROFLstomp things. The adventure mostly uses monsters of really low CR given this is for characters of level 17+. It's made more interesting by being underwater, which will likely hamper most weapon users, and the choice of monsters that get advantage on attack rolls once characters are below max HP. However, with water breathing readily given out, spellcasters will destroy those monsters with little effort. To increase the challenge, I gave every monster maximum hitpoints for its hit dice so that combats would last a few rounds.

My bigger disappointment doesn't lie as much with the author, though they could have adjusted things. The boss monster chosen is a CR17, but it's nothing more than a sack of HP and big attacks. Spellcasters shut it down quickly. For a creature like this, WotC should have given it legendary actions and saves, something the author could have added to it as has been done in other AL modules.

Overall, a good first look at world-changing power wielded by players and letting them be the badasses they are at this tier.

Several things I liked, the combat was a challenge for the group, but nothing they couldn't handle either. They lucked out and bypassed the "get to the island" fights by rolling all "ally" encounters. Having all the combat underwater isn't as big of a challenge to a T4 group as I suspect the author intended, and while "throws some large HP giants at things" is a decent stragety normally, it is somewhat solved by any party that happens to have a Horn of Valhalla handy (or 2) to call for reinforcements.

The Abolithic Soverignty was the big villain for 4e as I understand it, and this is the follow up to "What ever happened to our badguys"...as a whole, it works well.

You are given an interesting start to the mission which the players are sure to love, and then move quickly into making some tactical decisions regarding your journey. For the most part, the combats are not particularly challenging for folks of this level, so I made sure to have Roleplaying options available where I could talk about parts of the past lore with the players.

It helped them learn more about their world, and at the same time, the mod tracked nicely to some past edition adventures. It was well written, but a bit light on the combat challenges that some may want- while at the same time using a too often relied on trope for season 5 - you have to rush, rush, rush to find the answer....thus resource management should be critical...but you will have to adjust upwards most of these combats vs. spells commonly available at this level.

Overall, a great start for Tier 4

Overall a fun mod to run. This is a pretty combat-focused mod, but there's more opportunity for non-combat interaction than in some of the T3 mods we've seen. As the first AL T4 module, the adventure has to address both "Hey, we're in T4 now!" and "I haven't played this character in two years, how do I cast spells again?," and the first bit of the adventure does a pretty good job of that. Towards the end of this part, things break down a little, with a "final battle" than can be trivialized by a few spellcasters. For some parties - epecially spellcaster heavy ones - significantly beefing up the written combats will be required, while for "martial" parties the combats as written might be a time-consuming slog. Use the first half of the module to get a good idea of your player's power level (which might have very little to do with the APL/party size guidelines) and be prepared to change things on the fly. With a few changes, this is a really fun adventure to both play and run.

There are a few fun roleplay moments, but it's far to easy for more aggressive players to just brush past them, and the bulk of this mod is combat. And the combat itself is lackluster in a lot of ways. DMs should expect to be faced with the conundrum of either allowing spellcasting underwater, and finding a lot of fights trivialized, or disallowing it and finding them becoming unexpectedly brutal thanks to a reliance on hordes of weaker, CR 1/2 monsters. Mod seems to imply the former is what should apply, leading me to think the first few fights exist primarily to let the players realize just how far they've come. Run them cinematically, don't try and roll up actual initiative. Just let the players describe hacking and slashing. Don't get me wrong; the creatures they chose can be unexpectedly, surprisingly effective thanks to gaining advantage on wounded creatures. But it can be unexpectedly difficult to get that advantage against the tankier T4 characters out there, whose AC is pushing 25 and beyond. (Ooops, I shielded again... 30 and beyond!)

Ultimatly, this mod's 'interesting' combat scaling is also probably a result of the divide between the weaker, more roleplay oriented characters some players prefer, and the beefier, more combat-optimized characters other players prefer. Even the former will probably find this mod a touch easy. The latter? Be prepared to rewrite the entire module's worth of combats, just keep an eye on your time limit. Better yet, use this mod to guage the combat power of the group in preperation for part 2.