The deadliness of a weapon is inversely proportional how advanced it is.

Auto-cannons wielded by T600 terminators are only inconvenient.
Nuclear bombs can be survived just by hiding in a fridge.
Guns in general rarely actually kill people, the bigger and more advanced the gun the less likely to actually kill somebody.
Bows and arrows are deadly, even when used as melee weapons.
Anything that isn't a missile weapon trumps anything that is.

I'm pretty sure the destruction of the world will be achieved by somebody wielding nothing more than a thigh bone.

Oh there is an exception to this, low tech explosives are deadly even though they are clearly higher tech than some sharp pointy sticks.