So basically if the default skins didn’t exist, what other skins can replace them? I wanna know what you guys think are the skins (be it epic or legendary) that best represent the essence of the character.

No lore skins cause that would be too easy. Try fitting the skin for the character’s archetype. Like for example, I think Winged Victory Mercy would make as a great default because it really leans into Mercy’s angel aesthetic!