Yen'fay has an old fashioned and serious personality and enjoys meditation. He has deep loyalty to his country as he was willing to join forces with the Valm empire to stop further bloodshed of innocent lives. However, much of his loyalty was actually due to his love and care for his younger sister, Say'ri. Because of a deal struck with Excellus, Yen'fay begrudgingly obeyed the man who murdered his parents just to keep her safe. Yen'fay stubbornly refused to let Say'ri in on his plan to further ensure her safety. He took this plan to the grave, but was happy to see that his sister was amongst strong and kind people who would protect her and make her happy in his place.