Maou-sama no Machizukuri! ~Saikyou no Danjon wa Kindai Toshi~ - Volume 2 Chapter 12

The doomsday fell upon the earth when a dragon coffin sealed under a snow mountain for ages shifted, and the civilization of gods and devils began. The whole universe turned into a fantastic new world where everyone could rise to the top through cultivation. A lucky young boy seized the opportunity, and started his journey to be an overlord in cultivation.

- Description from Novelupdates

Ning Ruogong died to Zebras as he laid his hands on The Energy System, which reincarnated him to the Southern continent of the Planet Kumia.

How strong will he become after cultivating as an undying entity?

He, without doubt hates her.
What did she do to deserve his hate?
The person who she treated well like a brother did not even bother to notice it...

Years passed…

He needs to get married.
He needed a wife.
So she offered herself.
It was a marriage that will benefit both parties he said.

[The false necromancer has insufficient soldiers and is being ostracized and hunted. ]

[The real necromancer, countless skeletons, become the overlord of one party. ]

After Wu Heng obtained the double portal, he discovered that the original world was full of zombies.

When a gangster’s plan fails, another plan to survive begins.

Wu Heng chose to become a ‘Necromancer’.

Is it not allowed to summon the undead from another world? In the last days, the entire planet is a source of soldiers.

Can’t survive in the zombie world? Then I will live in another world and learn skills.

From then on, an undead army equipped with modern weapons appeared in the world.

Natural disaster strikes, millions of skeletons.

Immortal Bone Dragon, King of the Undead.

(Double portal + necromancer + magic + fantasy world + undead natural disaster.)

- Description from novelbuddy