The guardian daemons, ceustodaemons are easy to summon and relatively easy to control. But that “relatively” is key. If it is true that ceustodaemons are the souls of suicides, they’re happy to broaden their portfolio to include murder should their summoner lose control. Meanwhile, at the gaming table having three varieties with varying breath weapons will keep players on their toes.
A lesser ceustodaemon is almost suspiciously docile when summoned. It is under strict orders to behave, in order that it may spread as much disease as possible for its leukodaemon master.
A ceustodaemon seethes with hatred for the half-elven sorcerer who called him. After a century of unliving forgetfulness, his mortal memories come flooding back as he faces his former master—the man who drove him to suicide—still in control of him even now.
A greater ceustodaemon is summoned to defend a vault, but he lifts nary a clawed finger to defend the vault’s owner. After all, the sooner his master expires, the sooner he can drag the soul screaming to oblivion.
—Pathfinder Bestiary 2 XX