He strapped bandage tape around Natus's broken skull, and glued it tight with skin wrap, then he locked Dyognes's helmet over Natus's head. For the most part this was an effort to brace Natus's skull and keep it held in one piece, but Khiron adjusted the headgear settings as he reconnected the suit systems.
Natus raised his gloved hand to the side of his head.
'I can't give you eyes, old friend.' Khiron yelled above the din of fighting, 'but I can boost your hearing.'
He'd notched the helmet's auditory systems up to maximum gain. Though it now plucked at his pain threshold, Natus could hear every excruciating detail of the war around him. Sounds assailed him. He could distinguish between the grating hum of Astartes power armour and the jangling ring of greenskin mail. He could hear and feel howls and thundering footfalls as they washed in. Khiron pushed a reloaded bolter into Natus's hand.

Immediately, Natus shot two charging orks apart.

Brothers of the Snake