Roka

Roka was the lead knight of Carl and joined Avan's party against Hadlar. Maam was born from his union with Leira. He died at some point before Dai began his journey.

The prequel manga eventually revealed that Roka had died during the final battle at Hadlar's Underground Palace, due to the aftereffect of the last, cursed attack of Kigiro. Roka was nonetheless happy to have protected his best friend Avan until the very end and died happily knowing to having fulfilled his role.

Source: Dragon Quest Wiki