We know little of the previous history of Arioch, save his close connection with the Emperors of Melnibone. He was probably feared by most Melniboneans as they seem to have been reluctant even to utter his name.
Elric engaged in elaborate ceremonial ritual to summon Arioch the first time, Arioch agreeing to assist in locating Yyrkoon and rescue Cymoril in exchange for Elric's oath of service to him.
On subsequent occasions, Arioch often appeared upon Elric merely calling his name. Presumably he often acted to his own advantage, such as when he instructed Elric about how to acquire Stormbringer.
Despite his apparent power, Arioch could be bargained with as seen by his acquiescence to Elric's demand for Rackhir's release.
Arioch had the power to appear in many forms: a pair of floating eyes, a black faceless head, a fly, a beautiful youth clad in shimmering robe and wearing a slender sword and circlet of red fire on his head or an alien shape "both black and foul". Arioch's eyes in all forms were wise, old and evil.
Also known as the Knight of Swords, the Lord of the Darks and the
Keeper
of the Two Black Swords.
EI: 36, 69, 71, 81-86, 88, 126, 132-3,
139, 149, 169-172
A battle-barge was equipped with masts, sails, oars and catapults. Each bank of oars contained twenty to thirty oars per side and in some cases, e.g. the flagship Son of Pyaray had three independent steering systems.
Battle-barges were therefore very maneuverable and they often hid in grottoes of the Seamaze in order to spring on enemy ships unawares.
Except for their wooden decks, battle-barges were covered in gold
armor and therefore virtually indestructible (apparently gold is
a stronger metal in Elric's world than in our own). In addition,
they were capable of great speeds for the slaves who pulled the oars
were given a strength-enhancing drug which, however, killed them after
one day.
EI: 34, 62, 66, 79, 101
The Lords of Chaos, of whom Arioch was one, were said to be malicious. They apparently command great powers and many minions, among them dæmons and normal men warped by long servitude.
Most of the creatures of Chaos apparently lived on another plane of existence as they did not often appear on the earth.
The symbol of Chaos was eight arrows pointing in all directions.
EI: 9, 140,
142, 147-8, 172