Dragon's Eye wasn't too bad for Level One Jansens. Trolls, regular Yuan-ti and other mooks proved overcomeable by standard means; the likes of Cold Wights, for example, could only hit Ludwig with a 20 roll. The hairiest moment came from the Sword Spiders, who can basically shred a Jansen a round, but apparently they are well susceptible to Colour Spray and Command. Presio was a cakewalk, except the Jansens then chased her towards a trap that killed three of them (and her). Heh.
The big shift came with Level 5; the Yuan-ti Elite can hit my characters regularly, all of whom are two hits from death (three for Ludwig). Getting the Messenger of Sseth required getting lucky - the High Archer was near the door and was the only one to be lured out - and then pumping Ludwig with the Blur Deck and the Snakeoil Potion for -9 AC. Even then he was getting regularly hit, and really, the High Archer alone could have taken the entire party out (though I guess I could have whipped out some spell scrolls). Of course, then I still had to go in the room for the bloody +2 arrows...
Yxunomei herself. Well, the first time, a single cloudkill wiped the party.
Second time, lured away cloudkill with a precious Monster Summoning I scroll & shot away with Sseth bow, but -9AC Ludwig was chopped out by a Yxunomei nat 20 roll, and in any case there are too many spellcasters to stop.
Several tries later:
Pretty standard routine. Runner lures them round a corner so they bunch up, a monster summoning scroll set up a buffer while a horror scroll took out one of the priests. Rene Jansen, with his two Bow pips and the Gauntlets of Weapon Skill, went all in with Sseth on Yxunomei while others arrowed down the priests. Yxu went down early (as she tends to do when I fight her), but the sheer number of Yuan-ti Elite means the Level One Jansens can't keep up; once Ludwig goes down, almost everybody else dies to arrows within a round each.
Ultimately, Rene was left kiting like a motherfucker firing arrows at the last three Yuan-ti, using the party's only potion of heroism and even a pot of regeneration. Eventually their arrows ran out, but of course, the Jansens have about 8,000 arrows.
I'm sure there's easier ways to beat them, and this is nothing on the original Insane Level One run, but it's good to know the Jansens made it through with only two spell scrolls, three rare potions and a dozen healing potions.