Mount & Blade II: Bannerlord

Here are the steps in which I acquired this achievement:

#1. Have clan member(s) in your party (the more you have the easier this will be) and strip them of everything
#2. Find an enemy army that is besieging a town or castle with more troops than you
#3. Make a save before attacking the army - auto resolve the battle and hopefully the clan member(s) die
#4. Leave the battle and let the enemy army continue with the siege
#5. Use influence to make an army
#6. Attack the army which killed your clan member (this should be done before it disbands)
#7. After winning, acquire all the vassals from the enemy army (you can trade for them if in other parties in your army)
#8. Execute everyone (it should unlock) - if not go back to the original save in step #3.

It took me two tries to get this to pop. I had roughly 20 clan members in my party, and on the second attack of the enemy army two members died. I then followed the steps and after executing everyone it popped. Best of luck

Ive heard this this may have nothing to do with an RNG battle death, instead it may involve having an 18 year old heir, having the parent (you) getting captured and executed, then having the heir execute the lord. will confirm when it get it.

I’m still working on testing this, so if anyone wants to help then please comment with your results. Any fief and owner will do but what I did was besiege Hongard Castle over and over until I had -100 relations with Vartin’s clan (dey Jelind). Vartin’s party was close by so I rode up to him and created a new party with Niasen as the leader with no troops. I immediately talked to Niasen to “inspect troops” and dumped all my prisoners on him so he was slow lol. I made sure the settings for Clan member deaths was on Realistic and also enabled all Hero Deaths.

I created a save slot there and let Vartin’s party attack Niasen with the hopes he would die in combat, or possibly be executed since I had -100 relations (not even sure if that makes a difference). I reloaded about 30 times so far but haven’t seen Niasen die yet. I will load that save every now and then until I get lucky and Niasen dies. Then I’ll run down Vartin, capture and execute him. This also is contingent upon Vartin’s party killing Niasen in combat and not Vartin himself necessarily dealing the killing blow. Lot of variables to factor in here, so the more people that test this and post results will help!