Anyone trying to get the new white costumes for specific characters has likely already run into this issue. The Okris for “5 amount kills” and “kills in specific expedition” I think are great, but requiring specific parameters from an RNG system I think is a mistake. It can turn a fun reward that you get as you play into something you have to grind for, conversely making runs where no bosses you need show up feel like they were wasted – even compared to just before the update, where you had no overt reward at all.
This is heavily compounded by the weird selection of which grudgemarked boss shows up, and why the Minotaur is locked to only the Finale instead of being able to appear from any Chest of Trials – meaning you’d have to roll+restart for Skaven/Beastmen on the end of your Expedition to even have a chance, at which point he could still not show up.
I was playing with a group and we needed a Troll, eventually we just got fed up and rerolled the first tile on Cata until we got to the Chest and wiped if it wasn’t a troll, since we hadn’t got a troll in the previous 3 expeditions we played properly. It took us grinding that first tile for 40 minutes (5-6 rolls on opening the Chest of Trials) before we got a Troll.
The skins are a fun reward, rewarding players for fighting Grudgemarked bosses is fun, requiring players to get specific outcomes from an incredibly unpredictable, uncontrollable RNG system is not fun. (Not to mention, having to do it 17 times for all classes…)