nbamaniac said:
It is part of their divine contract on creation. The ultimate price of creating Nirn. Remember TES lore; Lorkan, an Aedra and the one most credited for creation died if I remember correctly.
First , daedra and aedra are the same beings a.k.a planets - aedra helped in the creation ,daedra didn't. Lorhkans and Magnus physical bodies , their planes ( planets) where destroyed in the creation of the physical world , but that could happen to every single one of them.
I don't know about Magus , but the divine part of Lorhkan we know exists in Sovngarde and is known to the nords as Shor.
Hafrael said:
(Lorkhan is almost literally Mundus, when his heart was destroyed, you were literally destroying the planet's heart. Think of it as a collaborative plane of Oblivion)
Actually , Mundus is the plane of existence , Nirn is the planet ... so it's kinda even worst than what you said.