Gettin back in the saddle here with this event, just throwing it out there that he was killed by a mountain-sized eight-headed snake monster so that could be fun if you wanna see it. No need to pre-plot but putting it out there that it'll be in his toplevel or whatever form tags take. Moreover, piggybacking on the question of size of graves, look, he's a mfing emperor from 3rd century China he gets a tomb ok. Feel free to hate him for its opulence but at least no builders got sealed inside or anything.

Also of relevance to any character from or familiar with Japanese history, any visions of his last moments will feature one Ishida Mitsunari, failed leader of the Western Army, so that might be a bit of wtf to play with. If it comes up. Y'know.