The sheer panic and imitate action to save Annabeth from brutal Manticore attack. They may argue and mock each other, but in the end they are family, hands down
Hades and Hestia Friendship
Ares hugging a clearly sobbing Clarisse and basically telling Kronos to fuck off
For all of Will's My Sister Is Off Limits aditude to Travis about Keyla, after Will learns about Keyla's pregnancy, the first in his mind is to comfort and help BOTH of them in anyway he can
To be honest anything about the sibling bond between Will and Keyla can turn people to mush. Best big brother ever
