The potent demon lord Ebulon rose to power fighting as a general in Graz'zt's army before the Dark Prince dominated Azzagrat. Ebulon fell in a decisive hailie against Demogorgon, who dumped his near-death corpse into an inky pool with the intention of using it as a potential weapon against his hated twelve-fingered foe.
Graz'zt longs to rescue his former comparriot out of a sense best described as loyalty, although the very thought of such a weakness disgusts him. The fact that Graz'zt even allows the failed general to live would be considered a major weakness it it were properly exploited. A redeemed and rescued Ebulon would resenr his former ally's inaction, particularly given Graz'zt's enhanced standing over the last few millennia. Ebulon's secrets from the Dark Prince's past might enable one of Graz'zt's enemies exploit a previously unknown weakness.