Madanach scales with the player up to level 50 so if you`re level 40 or under you can thrall him for a little while at least
good to know, as i am at level 40 right now. i'm in the middle of getting the elder scroll, so i've got at least another hour of that plus however long i goof off in blackreach on the way back before i can begin the forsworn conspiracy. i've already got weylin's note though, as i felt like he wouldn't mind me going through his things while he was thralled. i simply wont level up until i'm able to get into cihdna. does necromage effect dead thrall? i would assume it does, but my restoration isn't close to getting it. ah well lets get to my latest experiences.
after weylin died i left him since he was weak and annoying. i got the quest to get the reach jarl's shield or whatever and while there i got myself a decent level forsworn thrall. i'm drawing a blank on his title, pillager i want to say. after getting my house i set off to get the elder scroll, since i hadn't done that quest since my very first play through. the forsworn was moaning way more than seemed normal so i killed him off and left him. let me note that my second thrall this whole time has been a flame atronach that i summoned right after i got it. in the alftand ruins i ran into that drug addled khajiit and he put up a surprisingly good fight for being in clothes and wielding a woodcutting axe. i decided to make him my thrall but first, i placed the "blade of the reach" on his body which was an elven battleaxe no one was using. i didn't expect him to use it but low and behold, he did. he lasted up until one of those spinning blade traps that killed him and my atronach. i then ran back after him, and after dropping a few more choice pieces of equipment, rose him again. at this point i got hit by the trap myself and before i could heal i was dead.
no big deal i figured. i loaded back up not two minutes behind and all was good, until i looked behind me. both the cat and my atronach were gone. GONE. i tried not to panic and return to where they both died, nothing. now, understand i'm not getting worked up over a body. however, that axe was worth quite a bit! i am disappointed to say the least.
TL;DR: my thralls died, then i died. when game reloaded both thralls were nowhere to be seen, and items left on them were gone as well.
has this ever happened to anyone? i have a feeling that if i would have loaded up manually all would have been alright. i hadn't thought of that at the time, and it isn't worth losing an hour's progress to save my thrall's equipment.