Darius needs more work

Darius's captain called for his troops to retreat, but Darius refused to accept such an act of cowardice. Breaking formation, Darius strode towards the captain and decapitated him with one sweep of his gigantic axe. Both terrified and inspired, the soldiers followed Darius into battle and fought with incredible strength and fervor. After a long and grueling battle, they ultimately emerged victorious.

Noxian Guillotine If he kills an enemy with it, he and the assists on the kill get a short stacking (chain kills=more speed) movement speed boost while moving towards enemy champions (only for first 4 stacks). 5 stacks (pentakill) = even more speed or something else that

Both terrified and inspired, the soldiers followed Darius into battle and fought with incredible strength and fervor

does that

Apprehend It would fit if he would get reduced cooldown on E if he pulled enemies who have their back turned to him

Crippling strike

Darius's next attack strikes an enemy's crucial artery. As they bleed out...

This literary calls to increase the damage from his passive when he hits someone with it