I mean, if shuraka's bride died from poison or assassination that'd basically send the message that not only he's not able to protect not even those closest to him but that he's an easy target himself. it's political intrigue so obviously is not gonna be on the face but it makes sense.
also it's only chapter seven so it's going to take a while for all the pieces to come together
1. The assassination attempt on the wedding day was by all purposes meant to take out Shuraka and blame it on Tei's kingdom. It was never meant to kill them both. This is already stated in the chapter itself where Tei mentions that the poison was only lethal to children and caused only minor side effects in adults. So Tei would have survived had they both drank the poison. Shuraka the main target was supposed to die.
2. The assassination attempts weren't directed at Tei. It was more so that the chapters featured his ability to take out the assasins before they reached Shuraka. It was show casing his capabilities.
3. It is already stated: Shuraka's kingdom is more powerful. The King of Tei's kingdom could not refuse the marriage proposal without offending the more powerful kingdom. However he did not want to send his weak daughter either. So they needed someone of royal blood to go. This person rather than a "wife" is a hostage. They are living guarantee that the two nations will not betray each other even if they don't help each other.
Tbh Tei's kingdom expected Shuraka's to reject the marriage proposal after hearing that a "male" was coming. But Shuraka didn't so they had to roll along with it. So it wasn't that they were seeking benefits by rallying with Shuraka lol. They just couldn't refuse as the weaker nation.
On Shuraka's side, the aid already stated: They needed a bride of proper status that could back him up however that bride could not come from a nation equal to or MORE POWERFUL than Shuraka. They needed someone Shuraka could control.
However I'm pretty sure Shuraka developed some form of affection for Tei and did not want to use him so they shut off any potential aid. That's why the political alliance became mute.
Tei himself in the grand scheme of things does not matter (like most political brides). The big players are never the brides. They are bargaining chips as history has told for eons.
So as much as I wanna glorify this after reading it too many times, I will state this - the age gap doesn’t bother me. What bothered me though was Tei’s purpose the last 3 years he was with Shuraka. Like the panels showed most assasination attempts directed to him except their wedding day cos it was directed to both right. They didnt explain further why he should be disposed of because lets be realistic here 1. he a man who cant bear a child (so whats his purpose really- this aint abo) 2. what is his political significance aside from being an alliance. cos it hasn shown whether he manipulated the court in Arnata on his end. And when he returned to Leracal, he was useless as a political ally because he couldn’t do anything politically on his end to send support to Arnata (except prayers).
So I need more flashbacks else I’m dropping this. Cos I want me some delicious angst and exceptional storytelling… Like give me some juicy deets on the downlow the last 12 years…