Commander Cael was the head of the field command of the Alethi army facing that of the Parshendi in the battle between the two on the Shattered Plains before the Oathgate. He reported to Dalinar that HighprinceAladar had won his plateau, and that Aladar had said that the singing Parshendi had gone right down, letting him slaughter them.
Cael was commanded by Dalinar to send orders immediately to Aladar, Adolin, and General Khal.
He also pointed out to Dalinar the very beginning of the Everstorm, released by the combined singing Parshendi.
Cael was then directed to get everyone in the army moving, immediately.
Unfortunately, Cael fell in the clash between Everstorm and highstorm, almost making it to safety.