Who knows? Perhaps there are other powers beyond our collective ken that can keep the Underworld stable -- having it completely obliterated can be troublesome for the cycle of life, after all.

[ Apparently, the notion of punishment does not bother him one bit. ]

That choice, as to whether to put an end to something or to just put it off, brings another question: how did these so-called "Holy Wars" begin? [ Playing his hands by the pup's paws! One would think Shion were playing with a cat. ] Why seal -- or allow to be sealed -- for so many thousands of years than perhaps sparing several generations of Saints from having to fight in the first place?

[ Senility? Traces of it, perhaps. More like traces of a weary, centuries old mind. ]