Kill6BillionDemons II: The Successor's coming will be followed by 108 burning threads

[Eldan]

Not quiet inheritance - more like salvage. Maya abandoned her throne and he essentially got squatter's rights.

I had assumed that he was something like her second in command. He seems quite familiar with her, and he's also the one who rebuilt her army.

Speaking of low baselines for becoming one of hte seven... they are referred to as corpse-gods, amongst other things. It's pretty important for the mood of the story that they aren't grand in any way, but that they rule decaying remnants. They aren't the great first generation demiurges who ravaged the multiverse with fire and steel to build giant empires. They are what's left after everyone else killed each other, squatting in the ruins.