Kuroitsuki

Xion Aijawa thought his life was finally coming together. That is, until he tried saving a cat stuck in a tree, fell into a pit, and... died

In his disoriented sate of "Freshly dead" the silly Xion accepted a strange request and ended up transmigrating into the world full of dungeons and Mana. 

He became illegitimate child of Marquis family hated by his three siblings.

According to the memory of the original owner of the body, Xion only had a month to live.

So, taking the cover of the banquet, Xion ran away. Aided by a mysterious Mall System, he makes his way to the distant borderlands, hoping to put his past behind him. 

But fate has other plans-. Xion ends up saving Darius Rael Darkhelm, the feared Archduke of the North, notorious for his ruthless and deranged nature. 

The silly Xion tried to run away but...

 Xion's heart thumped loudly as Darius effortlessly pinned his wrists using only one hand.

"I've heard you tried to run away."

Darius gently caressed Xion's pale cheek, "That must be a lie... After all, I've given you things even the royal family can't have. Isn't that right, my dear healer?" 

Xion gulped when Darius's thumb brushed his lower lip as a chilling smirk remained on his handsome face.

 "I-I think I should leave, Your Grace. I've overstayed my welcome..."

The room grew cold, and struggling Xion shivered.

 Darius's green eyes dimmed before lighting up with a dangerous glint. 

Xion felt a pit growing in his stomach when he saw the deranged archduke smile. Darius never smiled. And whenever he did, it only meant trouble.

"You're right," Darius said calmly. "So, let's get married."

Xion "...!!!!"

[BL] Accidentally Becoming the Healer of the Deranged Archduke

After eating his fill and finally cooling his overcooked brain, Xion felt like he could think properly again.

He wiped his mouth with a napkin, then turned to the man sitting across from him. "Your Grace, can you show me your mana?"

Darius arched a brow at the sudden request but complied without question. With a snap of his fingers, a murky green flame flickered to life at his fingertips, twisting and curling like a restless serpent.

Xion's blue eyes reflected the eerie glow as he leaned in, studying the way it moved. Unsteady, wild, and untamed.

But he was too far away to observe properly. Without hesitation, he grabbed his chair and dragged it to the other side of the table, plopping himself down next to Darius.

As he slumped onto the seat, he gathered a very small amount of his own mana.

A soft white glow wrapped around the dark green tendrils like a mist.

Poisonous Mana