What do you think represents best this series??

Basically im making a list of all the tattoos i want to do in the future, with representations of my favourite media (miles morales, CSM, kaiju no8, SBY, etc.) Im looking for something that is relatively small, i dont want to cover my whole skin completely, and that strongly represents this series, so that when i would look at that small icon i would remember every moment, every life lesson, etc.

Do you guys know anything that can fit this description?