Emilia
Pack lovingly treats Emilia as his daughter and generally acts as father figure for the half-elf. In loops where Emilia died, Pack goes on an rampage, claiming that the world is worthless to him without her in it.
Natsuki Subaru
Pack has a positive friendship with Subaru, likely stemming from the boy's friendship with Emilia. However, in a loop where Subaru accidentally killed Emilia by telling her about Return from Death, Pack angrily froze him to death for breaking his promise with Emilia, returning to the mansion against her wishes, and being the one that killed her.