Greyjoy's Links
Greyjoy is an old friend of Davys estranged adopted son, Crixus. Greyjoy used to feel overshadowed by Crixus, always vying for the attention of Davy - which has led to resentment for Crixus in Greyjoy, and a thirst to prove he should've been Davys adopted son.
Davy cares for Greyjoy, in a way, but not as much as his adopted son. He realizes Greyjoys desire to prove himself, and tries to afford him opportunities to do so - but, by Davy's standards, Greyjoy always falls a bit short.
Greyjoy harbors a lot of animosity towards Crixus for always living in his shadow. At one time best friends, Greyjoy has no interest in rekindling a friendship. He believes Crixus to be wrong for choosing a different pirate crew over Chaos.
Once best friends and thicker than thieves, Crixus has a soft spot for Greyjoy. He believes Greyjoy is misguided, more worried about the approval of Davy than his own morality. If they meet again, Crixus knows it could come to a fight - though he hopes not.