It is already too late to make use of Don's warning. As the staff connects with Sigma's organic, atrophied ribs, there is an audible crack and Sigma bends about his stomach. He had not realized there was a pain worse than the eternal burn of a radiative bomb, but it was here, the dull and agonizing sensation of ruptured lungs and broken bones.

Before he can brace himself for another blow the sickle tears not through flesh, but grinds metal-against-metal, hooking into the titanium 'bones' of his cybernetic arm with a loud screech and ripping open false skin. Thick, white 'blood' spills from heavy fake muscle and without the means to clot, it drains from his arm and pools at his feet.

But beneath his shirt Sigma can feel his ribs bruise black and a winded gasp stands in for a scream. He raises his eyes to Don and tries to stretch the arm he had used to cradle his ribs towards him- a voiceless plea to run!

Gears whir beneath his ruined arm and he does his best to turn himself towards Terezi, trying to catch the staff's next blow in his machinelike claws but ultimately groping about the air in vain.