The final battle was a storm of grief and desperation. Coulson, his fatal wound now spreading across his chest like black lightning, knew his part. He had the serum that could give Daisy the edge—but it was the last of the Centipede formula. His only cure. He looked at Daisy, at the terrified young woman he’d raised into a leader, and he made his choice.
And Daisy, her powers surging, was the only one who could stop him. But a direct hit at full power, as the future had shown, would crack the planet. Marvel-s Agents of S.H.I.E.L.D. - Season 5
He faked giving her the serum. Instead, he injected himself. The final battle was a storm of grief and desperation