A Hot Mess of Good Ideas & Meh Execution
This feels like the biggest 'monkey's paw' DLC they've ever done, to me.
On one hand, Clanners don't spam elementals and light mechs everywhere anymore; On the other, many clan turrets and vehicles won't even show up on radar until you've passed them and then they backstab you with hard-hitting clantech weapons, which is arguably worse.
The mission roster against Clanners has been expanded, and they're mostly a welcome challenge, but the core problems with fighting against them are still unresolved; The principal behind clans as a faction is 'fewer, but tougher', but they frequently will send just as much if not more hardware at you than Inner Sphere factions whose hardware hits far weaker.
The most egregious example is Clan Raid missions, where successful completion has put me over 10 million C-Bills in the red more than once. The whole way that they function as a faction makes them a hard-counter to raids with faster-moving, lighter mechs as a concept; The light mechs they field are faster than anything you will probably bring, and WILL core you by shooting you in the back unless you turn to fight them, but when you fight them their heavier mechs catch up to you and eat you alive. This would be acceptable if the juice were worth the squeeze, but it often isn't. The payout is rarely worth the cored mechs, lost weapons, or dead pilots. The difficulty feels abritrary and artificial. This was true in Shadow of Kerensky but this DLC hasn't changed anything.
I'm not sure if 'Clan Defense' and 'Clan Warzone' missions are exclusive to Chaos Reign, or just the Clan era DLCs in general, but they were added in the update along with the DLC and they have the same problem, the payout is the same as fighting Inner Sphere factions but you'll usually be walking away from the mission wondering why you bothered.
On a lighter note, the new mechs fill out the Clan rosters nicely and are fun to use, and the new weapons do the same. The expanded vehicle roster adds some welcome variety to all factions in the game. There are even new Inner Sphere factions added, with their own mech variants, but the implementation feels kind of half-baked because their liveries don't cross over into the clan mechs they field, so half of their forces have their own exclusive color scheme and the other half have the basic uncustomized FDE pattern on them. The clan factions have this problem now as well, because the DLC adds Inner Sphere mechs kitted out with Clantech to their rosters and the paintjobs don't translate between IS and Clan stables.
The new mission type tasks you with completing as many objectives as possible on the largest generatable map before the OpFor drops an assault lance on your head, unfortunately it has the same problem as Rise of Rasalhague's infiltration missions where the time it takes to pursue side objectives isn't worth the reward the game gives you; If you like the idea of running a gauntlet on the biggest maps in the game, however, this one is for you.
The main story quest is split into two parts; The high-effort first half is an enjoyable callback to the old cornball 90s cartoon you can watch on the internet in some places. The second half is fun to play through, it's a gauntlet of harder missions in the vein of the first half of Dragon's Gambit, but the delivery leaves a bit to be desired; Unlike the other military operation DLCs, the only ones talking are your Commander and Ryana. A simple slideshow intro cutscene like the older DLCs would've helped, or some scattered one-liners from the FWL pilots you're fighting with, but the result feels kind of sterile compared to the desperate slugging match of Dragon's Gambit's first half.
You get three other side-missions as well in the vein of the side-missions from the HOTIS and Kestrel Lancers DLCs, they're fun to play through and you get more than an intro-exit blurb for each mission like in the Kestrel Lancers ones. One pits you against clanners and it feels properly tense, but the other two are more 'day in the life'-themed than something urgent like 'Bowen's Arrow' or 'Heir of Nothing'.
The soundtrack is mostly good again, no track is better than "The War Machine" from Shadow of Kerensky though. The best one this time is "The Adversary" IMO, followed by "Firepower", "A Different Path" & "The Handler" being good but not great, with "Final Dawn" taking last place with 'At least it's not Master of War'.
TL;DR - If I had to choose, I'd choose Shadow of Kerensky over this, but I'd choose this over Kestrel Lancers at the same price point.