You order him thrown into the dungeon. The guards drag him away as he shouts about dishonor, your questionable parentage, and so on.
1155 AD, Midwinter
Another day of working out minor domestic things with your noblemen. With Coronation Staff in your hand and the leaf-necklace on your torso, you're ready to help guide the Empire into bright future.
Suddenly, you feel terrible pain in your chest. You clutch the spot, feeling the absolutely alien warmth coming from the necklace. You scream in pain and fall to the ground, as few noblemen and guards rush to your side.
A wave of pain worse than moments before washes over your body and then your chest explodes in puff of crimson mist. The nobles scream in terror as a tree root has just brust from your innards! You scream for sweet release of death, but nothing comes of it. The root grows and you writhe in pain. Then the pain multiplies by thousands and you live through every second as second, third and further roots burst through orifices of your body; from your ear, from your penis and your anus. Blood pools undernearth your still alive body and bits of flesh hang from the bursted wounds like scraps from butcher's table.
The excruciating, absolutely gruesome spectacle continues for several minutes, and every tissue of your self experiences the pain as you writhe on the floor, the onlookers having no idea how to help you in any way.
Finally mercy arrives in most twisted of ways; a root bursts from your throat through your mouth, taking all the space, and letting you choke to death from lack of oxygen.
1155 AD. Few days later
Entirety of the court is in shambles. Thoroughly shaken, especially those nobles who witnessed Houlandin II's gruesome demise. It hasn't escaped some that the violent, root-related death of the Emperor came exactly at the time, to the very day and hour, of the opening of the strange honeycomb tomb. The corpse is entagled in numerous roots, of which one possesses a strange matrix of silvery veins around it tip, the tip adorned with only three small green leaves.
The Advisor strikes the table with the iron ball of authority.
"Noblemen of Methiant! Please calm yourselves down. As terrible and gruesome was the death of our short-lived Emperor, Houlandin II, we must concentrate and solve several issues, especially the matter of succession. His wife, Empress Herta, is pregnant with a child, of unknown gender. But there are two sons of Cyl, and the retired Emperor himself."
"Long live the long lived Emperor! He should take over the Empire!"
"No! We must wait till the child of the Empress leaves her womb first!"
"Fools! Just pass the Staff and Crown to Eivan, he will make a wise and just Emperor!"
"Take Saenn to the throne instead!"
CLANG CLANG CLANG! The Advisor speaks again:
"And what shall we do with the corpse of the Emperor? Ought we burn it to cinders and seal the ashes away?" The court murmurs, shouts and bemoans the fate of the Empire...
What will become of Yoean Dynasty now?
As for succession to the throne of Methiant...
A) We wait till Empress Herta gives birth, then we can consider a solution.
B) Return the throne to Emperor Cyl, for who knows how long. Hopefully only a short while.
C) Install Eivan as the next Emperor of Methiant.
D) Install Saenn as the next Emperor of Methiant.
As for the burial of Houlandin II...
A) Burn the root-infested corpse and seal the ashes far from the palace, just to be sure.
B) Even in this nightmarish state, the Emperor deserves proper burial in family tombs of Yoean dynasty.