#mantelopes

The Mourners found the other human species here and there but never interacted with them, merely watched to see if they are of benevolence or not. Moreso than anything, they were looked over for any Qu interaction or recent activity before passing over them. In the early times of the empire, the Mourners are 125% in hunting down their transformers. It is when the other species started to be uplifted by their own merits and join into alliances that the Mourners became involved. They closed the massive gaps between the species and became the 'parent' more or less as the ruling power, introducing them to their long history and situation. Just in time when the Gravitals were starting to become a threat that the Mourners weren't allowing.

They are caught before they became a real super power with their gravity weapons overpowering everyone.

The social intermingling between species with racism and whatnot is just expected and overtime overcome with the help of the wise and culling of lacking mercy on the Mourner's part.