Colt Darts to AE 17 and Fires a Missile at the hydra, Intending to seriously wound it.
Spoileraiming at the bit of hydra in AF23 so the blast is safely away from john.
(2d6) For hit
Also, assuming hit, no save, pushed away from me to the edge of the area.
Also, accounting for it's cold vulnerability, we've dealt (33+6+4+16) 59, or 43 after fast healing.