Yaiino was an engineer aboard the carrier Koramund. He served alongside Third Engineer Iaalu.
En route to a battle, the Koramund was ambushed by zerg fliers and crashed into the planet Vanass. Yaiino and the other engineers survived in the hanger bay, but were killed by Tenzaal, who had plotted to destroy Koramund. Iaalu would discover his corpse after the crash, and recognize his wounds as those from a psi-blade.
Reference
Kogge, Michael. "Carrier." (May 9, 2013). Blizzard Entertainment. StarCraft Lore: Carrier Accessed 2013-05-09