Just finished the Last of the Sarkorians DLC fully for the first time. Pretty underwhelming experience, to say the least. Aside from Ulbrig being introduced as a companion with his own dialogue interjections and party banter, content involves mostly just revisiting the same 3 areas in chapters 2 (only 1/3 areas), 3 and 5. I'm not going to judge the quality of writing and whether Ulbrig is a well-written and interesting character - that's extremely subjective, but personally I thought it was passable in the sense that Ulbrig seemed to fit reasonably well into the party narrative wise, although his rude interactions with cute and fluffy Nenio were extremely cringe.
Encounter design was mostly undead (both corporeal and incorporeal) and swarms with some demons here and there and felt extremely lazy. The whole DLC has only two encounters of note: Kabriri champions and the Sarkorian Kinslayer. Outside of these two encounters, everything else is just a forgettable pile of trash mobs that you mindlessly autoattack into chunky bits. It was nice of Owlcat to add Swarmbane Clasps to bypass swarm DR, but at the same time it felt like P2W cheating. I still prefer the tried and true method of bypassing swarm DR via Bane of Spirit damage conversion into Force.
The Kabriri pale champions are two boss tier enemies in chapter 3 you have to fight at the same time and kill within one round, otherwise they resurrect each other. One of them is a nasty spellcaster who needs to be immediately taken out of the fight before the battle even starts, the other is a melee attacker with a massive reflex save. Since both are undead, they have a myriad of immunities, but are still vulnerable to Prone. For me, the winning strategy was to Prone the caster with Winter's Grasp and then immediately rush to his position, waiting for the melee champion to close in and then tie him up with a tank:
While both are technically vulnerable to prone, the melee attacker's Reflex save is too high for him to be incapacitated reliably, though he can still drop on an unlucky save roll. Once both are engaged/incapacitated, beating them down is not an issue for a properly buffed dedicated damage dealer:
The Sarkorian Kinslayer was Owlcat's attempt at making a "non-standard" boss fight where they throw some gimmick mechanics at you. It's buffed by multiple totems that turn into spirit enemies when killed and you have to destroy the totems to remove the buffs... except you actually don't. If you have a beefy enough martial and a good cleric (and at this point in the game you probably do), you can just pre-drop the usual Guarded Hearth before the fight starts, then buff your martial with everything you have including Vision of Madness (Attack) and Touch of Good and boost your attack bonus into the stratosphere, way above the meager 100+ AC the Kinslayer has on unfair. Alternatively, you can just dispel all of his totem buffs despite the buffs being described as being granted "constantly" which to me sounds like they should be renewed instantly:
Once you dispel him, he still has a whole bucketload of immunities, but, surprisingly, he's not immune to Prone, which means he can be easily (by a fully dedicated and properly built DC caster) taken out of the fight via spells like Grease, Winter's Grasp and Sirocco:
Note that while he has the Spell Turning effect that reflects spells and spell-like abilities back at the caster, it doesn't affect AoE spells targeted on the ground and also does not affect the Touch of Law domain ability (forces the target to take 11 on most rolls including saves) since it's technically a buff and almost all single target buffs are accepted by enemies automatically due to being considered beneficial.
Alternatively, since this fight takes place in chapter 5 after you've potentially been to the Bladesmith's workshop, you can just outright Weird him with the Grandmaster's rod in one round:
Also, at the start of the fight, he seems to be hardcoded to attack Ulbrig which basically gives you a free round, if you grant Ulbrig Last Stand or make him tanky enough to not die in one flurry.
At the end of the DLC, you get to choose a nice popamole artifact (picture shamelessly stolen from ribbit):
I like the one with the elemental spell DC bonus the best. Works nicely for Sirocco, Greater Shout, Stormbolts and Mass Icy Prison.