Deke was a long time friend of Rho and boyfriend of Nishi. He dies by the Marad's hand during Corinthe's squad's attack on the 'Nox.
Rho first meets Deke while she was leaving for the Academy in Elara. In a memory, it's said that he was trying not to cry as he said goodbye to his sisters
All of which died on the attack on cancer sadly.
Aboard the ship Deke and Rho began to talk and made a pact. He'd be her brother and her his sister while they were away.