Morde - Yorick Ult Interactions

If yorick ults before morde, his ult is outside of shadow realm - makes sense

If yorick ults after morde ults, his ult is inside the shadow realm - makes sense

When morde ult ends, yorick's ult dies (while inside shadow realm)

You can qss/cleanse morde's ult while your ult is inside shadow realm and he doesn't die, why does he die when morde's ult ends naturally?

And while I'm bringing this up, are there any rioters looking into updating the ai of yoricks ult?

I have a cool idea for how to make it a little more interactive, but i'll save that for another post.