Known for his obsession with collecting personnel, Souma gathered
many capable retainers to his side. Because of this, rather than use common
groupings like the three dukes, the big four, the twelve divine generals, or
the twenty commanders, people came up with their own groupings.
One of these was the five great colored retainers. This was because a
number of Souma's retainers had aliases that involved a color.
The four who were universally agreed to belong to this group were
Liscia, the Golden Fortress of Ice, who was his devoted wife; Hakuya, the
Black-robed Prime Minister, who supported his policies; the Red Oni, Hal,
who distinguished himself on the battlefield; and the White Tactician, Julius
—so-called because of the white clothes he wore, which contrasted with
Hakuya's black, who supported him with military strategies. As for the
fifth, opinions were split on whether it should be Excel the Blue Sea
Princess, or Sebastian the Silver Deer.
Incidentally, Liscia's moniker, the Golden Fortress of Ice, came from her
days in the military academy where she'd coldly rejected all men who
approached her.
It is said that when she learned of this nickname, she nearly died of
embarrassment.