From Halopedia, the Halo wiki
He was extremely close to Ignatio Delgado. The Rubble Security Council entrusted Hollister and Delgado, for a limited amount of time, the navigation index to Earth and other human colonies. He and Delgado were attacked by three rogue Kig-Yar that lived on the Rubble. They engaged in a firefight, but Hollister was killed by a Kig-Yar with a plasma weapon. Before Delgado was killed, Spartan Adriana-111 intervened and killed the aliens.
Following his death, his parents harbored ill feelings toward Ignatio, as they had not wanted Melko to risk his life protecting the NAV data. His remains were cremated and then laid around in the Oaks Habitat in the Rubble.
Melko may be younger than Ignatio Delgado as Delgado called him mijo, a Spanish term meaning "My son" and is used by elders to call or beckoned younger males to them.
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