 The expedition proved to be a complete disaster, however, as all seven of the Argive champions were killed in the ensuing battle, except for Adrastus, who escaped thanks to his horse Arion, who was the fastest of all of his brethren.Diomedes' father, Tydeus, was among those who had been slain.Tydeus was Athena's favourite warrior at the time, and when he was dying she wanted to offer him a magic elixir (which she had obtained from her father) that would make him immortal.