PKing tricks and instant death must stay in Diablo 3.
I am not talking about hacks. Many of the best moments in my hardcore experience was surviving the impending (or so PK'ers had thought) doom after hostility sound. It rises challenge of survival to the new hights. If you want your journey to level 99 HC be safe, predictable, play private, solo, single player. Hydra sorces, trap assasins is a legend.
Instant death = extra strong fire enchanted, and oh the great multi shot lightning enchanted mobs before that combo was nerfed also dolls in act 3 which return damage inflicted back to you. Give back those brilliant moments and add new. It's bitter to die from them (hopefully you learnt something out of it) and it's fun to see someone else die knowing that could be you ... hadn't you fallen to one of those earlier and as a result became a better player. The wilder hardcore world is the better. Diablo 3 hardcore should be Diablo 2 hardcore ^ 2.