of course, everyone killed her
i thought about it for about 30 sec before i whacked her and i was a blessed good guy
A) it's just a game
B) the most powerful sword in the game

C) nothing gained by letting her live
D) you thought she was dead for years, why change it?
E) if i don't get the sword what was the point of this game?
i like this game - it's not my favorite, but if they wanted people to even consider letting her live they should have made some sort of benefit before ending game like a secret magic power or sister trains you - then you would have appreciated throwing the sword away
maybe one mission with the sword before you have to make the decision, i dunno - just something (imo)