So, reset all. He was never on Earth, BangSul never lost his memory, nor even met Kori and the others assassins at the pub.

The morning after they broke YeolMin and YooJin out of the Imperial Prison, the Prison Guards had to go to report to the Generals, and the Emperor, with tail between legs.
LianBi was curious, naturally. Nobody could know about Kori's powers and what kind of knowledge they had to succeed such thing, so if was very infuriating and humiliating.

As if that wasn't enough to damage the mood of LianBi, he also got reported by the same prison guards that the other two prostitutes that were arrested both died in their cell, during the attacks of other prisoners on their damage and that they were both group raped.
Naturally the Emperor deems the guards responsible for their negligence towards the defenceless and harmless prisoners and for them all punished very, very harshly. In addition to that, he also got all the prisoners who raped and killed the two tortured and executed in the worst possible ways.

The whole matter, in addition with the hairpin found in YooJin's place, only left him with huge bitterness. Most of all due to the unfairness of what happened to those two prisoners, it's something he can't stand. How could the prison guards let it happen? Does he seriously have to specify even the most obvious things when giving an order? And what was worse was that when the family of the two prostitutes were contacted to identify and take care of the corpses, both denied any involvement with those two poor men.

Now, believable or not, he is actually worried for the other two prostitutes, wondering if those who brought them out of prison had some evil plans for them too. That's the only reason why he ordered to hunt them down, with the categorical order to take them alive and unspoiled.

Soon enough, though, proof lead to the probable option that the escapist fled on Earth, since a portal was opened near Taifuan right on that same time.
The priests were able to determine the portal led to the city of Seoul, in South Korea, but that's not a good thing. LianBi can't send Imperial Guards or other armed forces to hunt them down on Earth, that would be an infraction of the international treaties.

After a couple of days from his arrival in Seoul, the mental magic expert from Heinmenhos arrives too, joining them at the apartment. Not even that person knows what the Emperor looks like and to keep his cover it's Norihiko to deal with the man who will have to attempt to bring back Bang-sul's lost memories.

LianBi feels terribly anxious about this whole matter, fearing that something could go wrong, although the expert assured that the worst that could happen is that the lost memories wouldn't come back. There is no real risk for life of health from the procedure. 'Lemon' himself agrees to go through it, feeling empty and frustrated due to the lack of memories.

After the magic is done, BangSul falls unconscious and the expert reassures it's normal and even a good sign, since it must mean that what be did had some effect indeed.

LianBi wanders around in the house, avoiding to be inside the room when he wakes up, since the memoryless BangSul doesn't seem to appreciate his presence at all. After an hour, he even decides to go to take a walk outside, since it could as well take many more hours before he wakes up.

www.roleplay.me/blog/151769

So... BangSul started to go out again, every couple of days. That's fine, he doesn't want him to feel imprisoned in the Palace, he himself feels the need to go out from time to time. Sadly he can never dedicate as much time as he would like to everyone, his family and his lover, due to the duties he has.
He reallly doesn't blame BangSul for going out, but spending a whole night outside without even warning seems a little... not quite right to him.

After spending the night in total anxiety, unable to find any rest before his husband returns, in the morning there is still no track of him.
I should calm down, he is an Avatar, he is surely powerful enough to push away whatever threat could come at him out in the city - he repeats himself, to trying to feel a bit reasured, but it doesn't work at all.
When it's time to start the morning routine, there is still nothing and he feels like to flip every table he sees.
While the eunuchs frantically run all over the Palace to see if he is somewhere there/warn the guards to send immediate notice when the Emperor Consort makes his return, LianBi heads to receive the morning regards from the high ranked members of the harem, as every morning before the meeting with the court in the Red Hall.

He is totally thoughtful and in a terrible mood, not even trying to hide it at all.

Since Song accepted, the marriage was set. He didn't even bother to mention anything to QinShi until the 'game was set'.
It was, basically, a 'you are getting married tomorrow' kind of announcement for the poor Grand Prince.
And as imaginable, he wasn't happy at all to receive the news. He even went to try to speak with LianBi, to explain his position and to convince him to change his mind, but the answer was 'you wanted to be in the Court, now live like a member of the Court'.

Rest was only forcedly getting prepared for the wedding by the servants and tailors.

Guessing that Song won't mind and since he doesn't want to make too much noise to reach the ears of all the annoying Sacred Blood around, LianBi decides the wedding to be quite discreet and private. A bit like Eun's wedding in Scarlet Heart, them two, the Emperor, MeiXi and the priests for the religious rite.

QinShi looks as happy as if he was taking part to his own funeral. He also looks stunned and somewhat overwhelmed by the whole thing.
Before the end of the ceremony, the Priestess of Sethi draw on their arms the special dot that will disappear on its own only after they consummate the wedding and that'd be the moment when the marriage would become official.
*It's a common thing in every marriage, not a special treatment for the 'happiest couple' in Xhuanghen.

Gifts for the couple, secret bets among the little eunuchs on how long will the marriage last, some food and off they go, to Zhou Palace.

When did he send QinShi away?
Days after their family was exterminated by the forces of the late General Yung.

Why?
At first it was to spare him from the horror of serving under the IAs with him, to keep him safe from everything that was supposed to come. He counted on taking him back as soon as he'd be on the throne. But then, the first years after the civil war weren't easy for him. There were still many dangerous people and traitors in the court, taking his little brother back didn't seem as a wise thing to do, as someone could use him to damage him or to blackmail him.
When his position as Emperor was finally stabilized, Kimahad'Ru declared war and he had to leave for the battlefields. What would be the point to take QinShi away from safety to get him into a nation at war?
Then...? The First Prince was born, almost casually. And LianBi's whole view on everything changed exponentially. Even more as the Second Prince came to life too and the various 'supporters' of the 'heirs' started to show up.
If there is one thing history taught is that the 'Grand Prince' never has a good end, that is, unless the Emperor and his Princes have a bad end before him.
LianBi realized that by then QinShi was close to become adult and that in truth he didn't know anything about what kind of person he grew to become. How could he trust him, where beside blood, he knew absolutely nothing about him?

So... he gave him protectors, he sent all the money that he could ever need, supported his every plan and decision, but never wanted him to return to Xhuanghen. He wanted him to have the best life he could have, just far away from the Court, where he could be corrupted and set-up.
He really didn't want him to come back at all, he hoped he'd eventually get himself a family and even forget about his older brother, but clearly that wasn't supposed to happen.

After his return to Xhuanghen was revealed and he was escorted to the Palace, LianBi's mood and frustration only worsened. He is genuinely worried that he could plot against his children and him to get to the throne, or that even if he was not like that, he'd just become another part of that war for the throne the three Princes are already inside of. Last he needs is another burden to carry, another person to be framed and pushed towards evil just to benefit the interest of some minister. He can't allow that.
If there is one thing he feels he must do immediately that is to get rid of his brother in some way. Naturally he will not get him killed nor harmed out of a future possibility, so he really needs to think.
But before that, he sent some Palace Guards to check the place where QinShi was staying.

What did they find there? A bunch of worrying substances that would let anyone guess he is under all sort of addictions.
LianBi orders the Alchemists of the nursery to check all those things to find out what it is.

Meanwhile, he also gets to hear that his nephew Song is looking for a convenient marriage to restore the honour of the Zhou family. Daebak! What a better candidate than the Grand Prince, the brother of the Emperor himself? Politically speaking, that's actually a very convenient marriage under every possible point of view, since it also strengthens the union between Huang and Zhou families, also indirectly benefitting the Second Prince.

He is in the throne room, waiting for the arrival of Song. He expects all sort of negative reaction but he is very well willing to force him, because he has to send that brat away from the Palace or he won't be able to sleep anymore.